MINSyntax: MIN([DISTINCT] expr) Returns the minimum value of expr. MIN() may take a string argument; in such cases, it returns the minimum string value. See http://dev.mysql.com/doc/refman/5.5/en/mysql-indexes.html. The DISTINCT keyword can be used to find the minimum of the distinct values of expr, however, this produces the same result as omitting DISTINCT. MIN() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html }mysql> SELECT student_name, MIN(test_score), MAX(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >JOIN MySQL supports the following JOIN syntaxes for the table_references part of SELECT statements and multiple-table DELETE and UPDATE statements: table_references: table_reference [, table_reference] ... table_reference: table_factor | join_table table_factor: tbl_name [[AS] alias] [index_hint_list] | table_subquery [AS] alias | ( table_references ) | { OJ table_reference LEFT OUTER JOIN table_reference ON conditional_expr } join_table: table_reference [INNER | CROSS] JOIN table_factor [join_condition] | table_reference STRAIGHT_JOIN table_factor | table_reference STRAIGHT_JOIN table_factor ON conditional_expr | table_reference {LEFT|RIGHT} [OUTER] JOIN table_reference join_condition | table_reference NATURAL [{LEFT|RIGHT} [OUTER]] JOIN table_factor join_condition: ON conditional_expr | USING (column_list) index_hint_list: index_hint [, index_hint] ... index_hint: USE {INDEX|KEY} [FOR {JOIN|ORDER BY|GROUP BY}] ([index_list]) | IGNORE {INDEX|KEY} [FOR {JOIN|ORDER BY|GROUP BY}] (index_list) | FORCE {INDEX|KEY} [FOR {JOIN|ORDER BY|GROUP BY}] (index_list) index_list: index_name [, index_name] ... A table reference is also known as a join expression. The syntax of table_factor is extended in comparison with the SQL Standard. The latter accepts only table_reference, not a list of them inside a pair of parentheses. This is a conservative extension if we consider each comma in a list of table_reference items as equivalent to an inner join. For example: SELECT * FROM t1 LEFT JOIN (t2, t3, t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c) is equivalent to: SELECT * FROM t1 LEFT JOIN (t2 CROSS JOIN t3 CROSS JOIN t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c) In MySQL, JOIN, CROSS JOIN, and INNER JOIN are syntactic equivalents (they can replace each other). In standard SQL, they are not equivalent. INNER JOIN is used with an ON clause, CROSS JOIN is used otherwise. In general, parentheses can be ignored in join expressions containing only inner join operations. MySQL also supports nested joins (see http://dev.mysql.com/doc/refman/5.5/en/nested-join-optimization.html). Index hints can be specified to affect how the MySQL optimizer makes use of indexes. For more information, see http://dev.mysql.com/doc/refman/5.5/en/index-hints.html. URL: http://dev.mysql.com/doc/refman/5.5/en/join.html rSELECT left_tbl.* FROM left_tbl LEFT JOIN right_tbl ON left_tbl.id = right_tbl.id WHERE right_tbl.id IS NULL; 0http://dev.mysql.com/doc/refman/5.5/en/join.htmlHEX%'Syntax: HEX(str), HEX(N) For a string argument str, HEX() returns a hexadecimal string representation of str where each character in str is converted to two hexadecimal digits. The inverse of this operation is performed by the UNHEX() function. For a numeric argument N, HEX() returns a hexadecimal string representation of the value of N treated as a longlong (BIGINT) number. This is equivalent to CONV(N,10,16). The inverse of this operation is performed by CONV(HEX(N),16,10). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT 0x616263, HEX('abc'), UNHEX(HEX('abc')); -> 'abc', 616263, 'abc' mysql> SELECT HEX(255), CONV(HEX(255),16,10); -> 'FF', 255 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlREPLACERSyntax: REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name [(col_name,...)] {VALUES | VALUE} ({expr | DEFAULT},...),(...),... Or: REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name SET col_name={expr | DEFAULT}, ... Or: REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name [(col_name,...)] SELECT ... REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted. See [HELP INSERT]. REPLACE is a MySQL extension to the SQL standard. It either inserts, or deletes and inserts. For another MySQL extension to standard SQL---that either inserts or updates---see http://dev.mysql.com/doc/refman/5.5/en/insert-on-duplicate.html. Note that unless the table has a PRIMARY KEY or UNIQUE index, using a REPLACE statement makes no sense. It becomes equivalent to INSERT, because there is no index to be used to determine whether a new row duplicates another. Values for all columns are taken from the values specified in the REPLACE statement. Any missing columns are set to their default values, just as happens for INSERT. You cannot refer to values from the current row and use them in the new row. If you use an assignment such as SET col_name = col_name + 1, the reference to the column name on the right hand side is treated as DEFAULT(col_name), so the assignment is equivalent to SET col_name = DEFAULT(col_name) + 1. To use REPLACE, you must have both the INSERT and DELETE privileges for the table. URL: http://dev.mysql.com/doc/refman/5.5/en/replace.html 3http://dev.mysql.com/doc/refman/5.5/en/replace.htmlCONTAINS3Contains(g1,g2) Returns 1 or 0 to indicate whether g1 completely contains g2. This tests the opposite relationship as Within(). URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometriesSRID$eSRID(g) Returns an integer indicating the Spatial Reference System ID for the geometry value g. In MySQL, the SRID value is just an integer associated with the geometry value. All calculations are done assuming Euclidean (planar) geometry. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions 7mysql> SELECT SRID(GeomFromText('LineString(1 1,2 2)',101)); +-----------------------------------------------+ | SRID(GeomFromText('LineString(1 1,2 2)',101)) | +-----------------------------------------------+ | 101 | +-----------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functionsCURRENT_TIMESTAMPSyntax: CURRENT_TIMESTAMP, CURRENT_TIMESTAMP() CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlSHOW CONTRIBUTORS)Syntax: SHOW CONTRIBUTORS The SHOW CONTRIBUTORS statement displays information about the people who contribute to MySQL source or to causes that we support. For each contributor, it displays Name, Location, and Comment values. URL: http://dev.mysql.com/doc/refman/5.5/en/show-contributors.html =http://dev.mysql.com/doc/refman/5.5/en/show-contributors.htmlzVARIANCE(Syntax: VARIANCE(expr) Returns the population standard variance of expr. This is an extension to standard SQL. The standard SQL function VAR_POP() can be used instead. VARIANCE() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html  DROP SERVER'Syntax: DROP SERVER [ IF EXISTS ] server_name Drops the server definition for the server named server_name. The corresponding row within the mysql.servers table will be deleted. This statement requires the SUPER privilege. Dropping a server for a table does not affect any FEDERATED tables that used this connection information when they were created. See [HELP CREATE SERVER]. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-server.html 7http://dev.mysql.com/doc/refman/5.5/en/drop-server.html; SHOW AUTHORSSyntax: SHOW AUTHORS The SHOW AUTHORS statement displays information about the people who work on MySQL. For each author, it displays Name, Location, and Comment values. URL: http://dev.mysql.com/doc/refman/5.5/en/show-authors.html 8http://dev.mysql.com/doc/refman/5.5/en/show-authors.htmlH VAR_SAMPSyntax: VAR_SAMP(expr) Returns the sample variance of expr. That is, the denominator is the number of rows minus one. VAR_SAMP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html CONCAT%Syntax: CONCAT(str1,str2,...) Returns the string that results from concatenating the arguments. May have one or more arguments. If all arguments are nonbinary strings, the result is a nonbinary string. If the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent string form. This is a nonbinary string as of MySQL 5.5.3. Before 5.5.3, it is a binary string; to to avoid that and produce a nonbinary string, you can use an explicit type cast, as in this example: SELECT CONCAT(CAST(int_col AS CHAR), char_col); CONCAT() returns NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT CONCAT('My', 'S', 'QL'); -> 'MySQL' mysql> SELECT CONCAT('My', NULL, 'QL'); -> NULL mysql> SELECT CONCAT(14.3); -> '14.3' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlF GEOMETRY HIERARCHY"Geometry is the base class. It is an abstract class. The instantiable subclasses of Geometry are restricted to zero-, one-, and two-dimensional geometric objects that exist in two-dimensional coordinate space. All instantiable geometry classes are defined so that valid instances of a geometry class are topologically closed (that is, all defined geometries include their boundary). The base Geometry class has subclasses for Point, Curve, Surface, and GeometryCollection: o Point represents zero-dimensional objects. o Curve represents one-dimensional objects, and has subclass LineString, with sub-subclasses Line and LinearRing. o Surface is designed for two-dimensional objects and has subclass Polygon. o GeometryCollection has specialized zero-, one-, and two-dimensional collection classes named MultiPoint, MultiLineString, and MultiPolygon for modeling geometries corresponding to collections of Points, LineStrings, and Polygons, respectively. MultiCurve and MultiSurface are introduced as abstract superclasses that generalize the collection interfaces to handle Curves and Surfaces. Geometry, Curve, Surface, MultiCurve, and MultiSurface are defined as noninstantiable classes. They define a common set of methods for their subclasses and are included for extensibility. Point, LineString, Polygon, GeometryCollection, MultiPoint, MultiLineString, and MultiPolygon are instantiable classes. URL: http://dev.mysql.com/doc/refman/5.5/en/gis-geometry-class-hierarchy.html Hhttp://dev.mysql.com/doc/refman/5.5/en/gis-geometry-class-hierarchy.htmle CHAR FUNCTION%Syntax: CHAR(N,... [USING charset_name]) CHAR() interprets each argument N as an integer and returns a string consisting of the characters given by the code values of those integers. NULL values are skipped. By default, CHAR() returns a binary string. To produce a string in a given character set, use the optional USING clause: mysql> SELECT CHARSET(CHAR(0x65)), CHARSET(CHAR(0x65 USING utf8)); +---------------------+--------------------------------+ | CHARSET(CHAR(0x65)) | CHARSET(CHAR(0x65 USING utf8)) | +---------------------+--------------------------------+ | binary | utf8 | +---------------------+--------------------------------+ If USING is given and the result string is illegal for the given character set, a warning is issued. Also, if strict SQL mode is enabled, the result from CHAR() becomes NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html omysql> SELECT CHAR(77,121,83,81,'76'); -> 'MySQL' mysql> SELECT CHAR(77,77.3,'77.3'); -> 'MMM' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlDATETIMESDATETIME A date and time combination. The supported range is '1000-01-01 00:00:00' to '9999-12-31 23:59:59'. MySQL displays DATETIME values in 'YYYY-MM-DD HH:MM:SS' format, but permits assignment of values to DATETIME columns using either strings or numbers. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.htmlSHOW CREATE TRIGGERSyntax: SHOW CREATE TRIGGER trigger_name This statement shows a CREATE TRIGGER statement that creates the given trigger. URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-trigger.html ?http://dev.mysql.com/doc/refman/5.5/en/show-create-trigger.html&SHOW CREATE PROCEDURE^Syntax: SHOW CREATE PROCEDURE proc_name This statement is a MySQL extension. It returns the exact string that can be used to re-create the named stored procedure. A similar statement, SHOW CREATE FUNCTION, displays information about stored functions (see [HELP SHOW CREATE FUNCTION]). Both statements require that you be the owner of the routine or have SELECT access to the mysql.proc table. If you do not have privileges for the routine itself, the value displayed for the Create Procedure or Create Function field will be NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-procedure.html dmysql> SHOW CREATE PROCEDURE test.simpleproc\G *************************** 1. row *************************** Procedure: simpleproc sql_mode: Create Procedure: CREATE PROCEDURE `simpleproc`(OUT param1 INT) BEGIN SELECT COUNT(*) INTO param1 FROM t; END character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci mysql> SHOW CREATE FUNCTION test.hello\G *************************** 1. row *************************** Function: hello sql_mode: Create Function: CREATE FUNCTION `hello`(s CHAR(20)) RETURNS CHAR(50) RETURN CONCAT('Hello, ',s,'!') character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci Ahttp://dev.mysql.com/doc/refman/5.5/en/show-create-procedure.htmlOPENSyntax: OPEN cursor_name This statement opens a previously declared cursor. For an example, see http://dev.mysql.com/doc/refman/5.5/en/cursors.html. URL: http://dev.mysql.com/doc/refman/5.5/en/open.html 0http://dev.mysql.com/doc/refman/5.5/en/open.htmlINTEGERINTEGER[(M)] [UNSIGNED] [ZEROFILL] This type is a synonym for INT. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlLOWER%MSyntax: LOWER(str) Returns the string str with all characters changed to lowercase according to the current character set mapping. The default is latin1 (cp1252 West European). mysql> SELECT LOWER('QUADRATICALLY'); -> 'quadratically' LOWER() (and UPPER()) are ineffective when applied to binary strings (BINARY, VARBINARY, BLOB). To perform lettercase conversion, convert the string to a nonbinary string: mysql> SET @str = BINARY 'New York'; mysql> SELECT LOWER(@str), LOWER(CONVERT(@str USING latin1)); +-------------+-----------------------------------+ | LOWER(@str) | LOWER(CONVERT(@str USING latin1)) | +-------------+-----------------------------------+ | New York | new york | +-------------+-----------------------------------+ URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html SHOW COLUMNSGSyntax: SHOW [FULL] COLUMNS {FROM | IN} tbl_name [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW COLUMNS displays information about the columns in a given table. It also works for views. The LIKE clause, if present, indicates which column names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. SHOW COLUMNS displays information only for those columns for which you have some privilege. mysql> SHOW COLUMNS FROM City; +------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+----------+------+-----+---------+----------------+ | Id | int(11) | NO | PRI | NULL | auto_increment | | Name | char(35) | NO | | | | | Country | char(3) | NO | UNI | | | | District | char(20) | YES | MUL | | | | Population | int(11) | NO | | 0 | | +------------+----------+------+-----+---------+----------------+ 5 rows in set (0.00 sec) If the data types differ from what you expect them to be based on a CREATE TABLE statement, note that MySQL sometimes changes data types when you create or alter a table. The conditions under which this occurs are described in http://dev.mysql.com/doc/refman/5.5/en/silent-column-changes.html. The FULL keyword causes the output to include the column collation and comments, as well as the privileges you have for each column. You can use db_name.tbl_name as an alternative to the tbl_name FROM db_name syntax. In other words, these two statements are equivalent: mysql> SHOW COLUMNS FROM mytable FROM mydb; mysql> SHOW COLUMNS FROM mydb.mytable; SHOW COLUMNS displays the following values for each table column: Field indicates the column name. Type indicates the column data type. Collation indicates the collation for nonbinary string columns, or NULL for other columns. This value is displayed only if you use the FULL keyword. The Null field contains YES if NULL values can be stored in the column, NO if not. The Key field indicates whether the column is indexed: o If Key is empty, the column either is not indexed or is indexed only as a secondary column in a multiple-column, nonunique index. o If Key is PRI, the column is a PRIMARY KEY or is one of the columns in a multiple-column PRIMARY KEY. o If Key is UNI, the column is the first column of a UNIQUE index. (A UNIQUE index permits multiple NULL values, but you can tell whether the column permits NULL by checking the Null field.) o If Key is MUL, the column is the first column of a nonunique index in which multiple occurrences of a given value are permitted within the column. If more than one of the Key values applies to a given column of a table, Key displays the one with the highest priority, in the order PRI, UNI, MUL. A UNIQUE index may be displayed as PRI if it cannot contain NULL values and there is no PRIMARY KEY in the table. A UNIQUE index may display as MUL if several columns form a composite UNIQUE index; although the combination of the columns is unique, each column can still hold multiple occurrences of a given value. The Default field indicates the default value that is assigned to the column. This is NULL if the column has an explicit default of NULL, or if the column definition has no DEFAULT clause. The Extra field contains any additional information that is available about a given column. The value is nonempty in these cases: auto_increment for columns that have the AUTO_INCREMENT attribute; on update CURRENT_TIMESTAMP for TIMESTAMP columns that have the ON UPDATE CURRENT_TIMESTAMP attribute. Privileges indicates the privileges you have for the column. This value is displayed only if you use the FULL keyword. Comment indicates any comment the column has. This value is displayed only if you use the FULL keyword. SHOW FIELDS is a synonym for SHOW COLUMNS. You can also list a table's columns with the mysqlshow db_name tbl_name command. The DESCRIBE statement provides information similar to SHOW COLUMNS. See [HELP DESCRIBE]. The SHOW CREATE TABLE, SHOW TABLE STATUS, and SHOW INDEX statements also provide information about tables. See [HELP SHOW]. URL: http://dev.mysql.com/doc/refman/5.5/en/show-columns.html 8http://dev.mysql.com/doc/refman/5.5/en/show-columns.htmlCREATE TRIGGER'Syntax: CREATE [DEFINER = { user | CURRENT_USER }] TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW trigger_body This statement creates a new trigger. A trigger is a named database object that is associated with a table, and that activates when a particular event occurs for the table. The trigger becomes associated with the table named tbl_name, which must refer to a permanent table. You cannot associate a trigger with a TEMPORARY table or a view. CREATE TRIGGER requires the TRIGGER privilege for the table associated with the trigger. The statement might also require the SUPER privilege, depending on the DEFINER value, as described later in this section. If binary logging is enabled, CREATE TRIGGER might require the SUPER privilege, as described in http://dev.mysql.com/doc/refman/5.5/en/stored-programs-logging.html. The DEFINER clause determines the security context to be used when checking access privileges at trigger activation time. See later in this section for more information. trigger_time is the trigger action time. It can be BEFORE or AFTER to indicate that the trigger activates before or after each row to be modified. trigger_event indicates the kind of statement that activates the trigger. The trigger_event can be one of the following: o INSERT: The trigger is activated whenever a new row is inserted into the table; for example, through INSERT, LOAD DATA, and REPLACE statements. o UPDATE: The trigger is activated whenever a row is modified; for example, through UPDATE statements. o DELETE: The trigger is activated whenever a row is deleted from the table; for example, through DELETE and REPLACE statements. However, DROP TABLE and TRUNCATE TABLE statements on the table do not activate this trigger, because they do not use DELETE. Dropping a partition does not activate DELETE triggers, either. See [HELP TRUNCATE TABLE]. URL: http://dev.mysql.com/doc/refman/5.5/en/create-trigger.html :http://dev.mysql.com/doc/refman/5.5/en/create-trigger.htmlMONTHSyntax: MONTH(date) Returns the month for date, in the range 1 to 12 for January to December, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero month part. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 0mysql> SELECT MONTH('2008-02-03'); -> 2 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlTINYINTTINYINT[(M)] [UNSIGNED] [ZEROFILL] A very small integer. The signed range is -128 to 127. The unsigned range is 0 to 255. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html SHOW TRIGGERS1Syntax: SHOW TRIGGERS [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW TRIGGERS lists the triggers currently defined for tables in a database (the default database unless a FROM clause is given). This statement returns results only for databases and tables for which you have the TRIGGER privilege. The LIKE clause, if present, indicates which table names to match and causes the statement to display triggers for those tables. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. For the trigger ins_sum as defined in http://dev.mysql.com/doc/refman/5.5/en/triggers.html, the output of this statement is as shown here: mysql> SHOW TRIGGERS LIKE 'acc%'\G *************************** 1. row *************************** Trigger: ins_sum Event: INSERT Table: account Statement: SET @sum = @sum + NEW.amount Timing: BEFORE Created: NULL sql_mode: Definer: myname@localhost character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci character_set_client is the session value of the character_set_client system variable when the trigger was created. collation_connection is the session value of the collation_connection system variable when the trigger was created. Database Collation is the collation of the database with which the trigger is associated. URL: http://dev.mysql.com/doc/refman/5.5/en/show-triggers.html 9http://dev.mysql.com/doc/refman/5.5/en/show-triggers.html/MASTER_POS_WAITSyntax: MASTER_POS_WAIT(log_name,log_pos[,timeout]) This function is useful for control of master/slave synchronization. It blocks until the slave has read and applied all updates up to the specified position in the master log. The return value is the number of log events the slave had to wait for to advance to the specified position. The function returns NULL if the slave SQL thread is not started, the slave's master information is not initialized, the arguments are incorrect, or an error occurs. It returns -1 if the timeout has been exceeded. If the slave SQL thread stops while MASTER_POS_WAIT() is waiting, the function returns NULL. If the slave is past the specified position, the function returns immediately. If a timeout value is specified, MASTER_POS_WAIT() stops waiting when timeout seconds have elapsed. timeout must be greater than 0; a zero or negative timeout means no timeout. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlREGEXP%\Syntax: expr REGEXP pat, expr RLIKE pat Performs a pattern match of a string expression expr against a pattern pat. The pattern can be an extended regular expression. The syntax for regular expressions is discussed in http://dev.mysql.com/doc/refman/5.5/en/regexp.html. Returns 1 if expr matches pat; otherwise it returns 0. If either expr or pat is NULL, the result is NULL. RLIKE is a synonym for REGEXP, provided for mSQL compatibility. The pattern need not be a literal string. For example, it can be specified as a string expression or table column. *Note*: Because MySQL uses the C escape syntax in strings (for example, "\n" to represent the newline character), you must double any "\" that you use in your REGEXP strings. REGEXP is not case sensitive, except when used with binary strings. URL: http://dev.mysql.com/doc/refman/5.5/en/regexp.html mysql> SELECT 'Monty!' REGEXP '.*'; -> 1 mysql> SELECT 'new*\n*line' REGEXP 'new\\*.\\*line'; -> 1 mysql> SELECT 'a' REGEXP 'A', 'a' REGEXP BINARY 'A'; -> 1 0 mysql> SELECT 'a' REGEXP '^[a-d]'; -> 1 2http://dev.mysql.com/doc/refman/5.5/en/regexp.htmlq IF STATEMENT+Syntax: IF search_condition THEN statement_list [ELSEIF search_condition THEN statement_list] ... [ELSE statement_list] END IF The IF statement for stored programs implements a basic conditional construct. *Note*: There is also an IF() function, which differs from the IF statement described here. See http://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html. The IF statement can have THEN, ELSE, and ELSEIF clauses, and it is terminated with END IF. If the search_condition evaluates to true, the corresponding THEN or ELSEIF clause statement_list executes. If no search_condition matches, the ELSE clause statement_list executes. Each statement_list consists of one or more SQL statements; an empty statement_list is not permitted. URL: http://dev.mysql.com/doc/refman/5.5/en/if.html .http://dev.mysql.com/doc/refman/5.5/en/if.html^YSyntax: ^ Bitwise XOR: URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html gmysql> SELECT 1 ^ 1; -> 0 mysql> SELECT 1 ^ 0; -> 1 mysql> SELECT 11 ^ 3; -> 8 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html DROP VIEW'Syntax: DROP VIEW [IF EXISTS] view_name [, view_name] ... [RESTRICT | CASCADE] DROP VIEW removes one or more views. You must have the DROP privilege for each view. If any of the views named in the argument list do not exist, MySQL returns an error indicating by name which nonexisting views it was unable to drop, but it also drops all of the views in the list that do exist. The IF EXISTS clause prevents an error from occurring for views that don't exist. When this clause is given, a NOTE is generated for each nonexistent view. See [HELP SHOW WARNINGS]. RESTRICT and CASCADE, if given, are parsed and ignored. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-view.html 5http://dev.mysql.com/doc/refman/5.5/en/drop-view.htmlWITHIN3Within(g1,g2) Returns 1 or 0 to indicate whether g1 is spatially within g2. This tests the opposite relationship as Contains(). URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries  WEEKSyntax: WEEK(date[,mode]) This function returns the week number for date. The two-argument form of WEEK() enables you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the value of the default_week_format system variable is used. See http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT WEEK('2008-02-20'); -> 7 mysql> SELECT WEEK('2008-02-20',0); -> 7 mysql> SELECT WEEK('2008-02-20',1); -> 8 mysql> SELECT WEEK('2008-12-31',1); -> 53 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html! SHOW PLUGINSSyntax: SHOW PLUGINS SHOW PLUGINS displays information about server plugins. Plugin information is also available in the INFORMATION_SCHEMA.PLUGINS table. See http://dev.mysql.com/doc/refman/5.5/en/plugins-table.html. Example of SHOW PLUGINS output: mysql> SHOW PLUGINS\G *************************** 1. row *************************** Name: binlog Status: ACTIVE Type: STORAGE ENGINE Library: NULL License: GPL *************************** 2. row *************************** Name: CSV Status: ACTIVE Type: STORAGE ENGINE Library: NULL License: GPL *************************** 3. row *************************** Name: MEMORY Status: ACTIVE Type: STORAGE ENGINE Library: NULL License: GPL *************************** 4. row *************************** Name: MyISAM Status: ACTIVE Type: STORAGE ENGINE Library: NULL License: GPL ... URL: http://dev.mysql.com/doc/refman/5.5/en/show-plugins.html 8http://dev.mysql.com/doc/refman/5.5/en/show-plugins.html"DROP FUNCTION UDFSyntax: DROP FUNCTION function_name This statement drops the user-defined function (UDF) named function_name. To drop a function, you must have the DELETE privilege for the mysql database. This is because DROP FUNCTION removes a row from the mysql.func system table that records the function's name, type, and shared library name. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-function-udf.html =http://dev.mysql.com/doc/refman/5.5/en/drop-function-udf.htmlW#PREPARESyntax: PREPARE stmt_name FROM preparable_stmt The PREPARE statement prepares a statement and assigns it a name, stmt_name, by which to refer to the statement later. Statement names are not case sensitive. preparable_stmt is either a string literal or a user variable that contains the text of the statement. The text must represent a single SQL statement, not multiple statements. Within the statement, "?" characters can be used as parameter markers to indicate where data values are to be bound to the query later when you execute it. The "?" characters should not be enclosed within quotation marks, even if you intend to bind them to string values. Parameter markers can be used only where data values should appear, not for SQL keywords, identifiers, and so forth. If a prepared statement with the given name already exists, it is deallocated implicitly before the new statement is prepared. This means that if the new statement contains an error and cannot be prepared, an error is returned and no statement with the given name exists. A prepared statement is executed with EXECUTE and released with DEALLOCATE PREPARE. The scope of a prepared statement is the session within which it is created. Other sessions cannot see it. URL: http://dev.mysql.com/doc/refman/5.5/en/prepare.html 3http://dev.mysql.com/doc/refman/5.5/en/prepare.htmlo$LOCK(Syntax: LOCK TABLES tbl_name [[AS] alias] lock_type [, tbl_name [[AS] alias] lock_type] ... lock_type: READ [LOCAL] | [LOW_PRIORITY] WRITE UNLOCK TABLES MySQL enables client sessions to acquire table locks explicitly for the purpose of cooperating with other sessions for access to tables, or to prevent other sessions from modifying tables during periods when a session requires exclusive access to them. A session can acquire or release locks only for itself. One session cannot acquire locks for another session or release locks held by another session. Locks may be used to emulate transactions or to get more speed when updating tables. This is explained in more detail later in this section. LOCK TABLES explicitly acquires table locks for the current client session. Table locks can be acquired for base tables or views. You must have the LOCK TABLES privilege, and the SELECT privilege for each object to be locked. For view locking, LOCK TABLES adds all base tables used in the view to the set of tables to be locked and locks them automatically. If you lock a table explicitly with LOCK TABLES, any tables used in triggers are also locked implicitly, as described in http://dev.mysql.com/doc/refman/5.5/en/lock-tables-and-triggers.html. UNLOCK TABLES explicitly releases any table locks held by the current session. LOCK TABLES implicitly releases any table locks held by the current session before acquiring new locks. Another use for UNLOCK TABLES is to release the global read lock acquired with the FLUSH TABLES WITH READ LOCK statement, which enables you to lock all tables in all databases. See [HELP FLUSH]. (This is a very convenient way to get backups if you have a file system such as Veritas that can take snapshots in time.) URL: http://dev.mysql.com/doc/refman/5.5/en/lock-tables.html 7http://dev.mysql.com/doc/refman/5.5/en/lock-tables.html`% UPDATEXML%Syntax: UpdateXML(xml_target, xpath_expr, new_xml) This function replaces a single portion of a given fragment of XML markup xml_target with a new XML fragment new_xml, and then returns the changed XML. The portion of xml_target that is replaced matches an XPath expression xpath_expr supplied by the user. In MySQL 5.5, the XPath expression can contain at most 127 characters. (This limitation is lifted in MySQL 5.6.) If no expression matching xpath_expr is found, or if multiple matches are found, the function returns the original xml_target XML fragment. All three arguments should be strings. URL: http://dev.mysql.com/doc/refman/5.5/en/xml-functions.html vmysql> SELECT -> UpdateXML('ccc', '/a', 'fff') AS val1, -> UpdateXML('ccc', '/b', 'fff') AS val2, -> UpdateXML('ccc', '//b', 'fff') AS val3, -> UpdateXML('ccc', '/a/d', 'fff') AS val4, -> UpdateXML('ccc', '/a/d', 'fff') AS val5 -> \G *************************** 1. row *************************** val1: fff val2: ccc val3: fff val4: cccfff val5: ccc 9http://dev.mysql.com/doc/refman/5.5/en/xml-functions.html& RESET SLAVElSyntax: RESET SLAVE [ALL] RESET SLAVE makes the slave forget its replication position in the master's binary log. This statement is meant to be used for a clean start: It deletes the master.info and relay-log.info files, all the relay log files, and starts a new relay log file. To use RESET SLAVE, the slave replication threads must be stopped (use STOP SLAVE if necessary). *Note*: All relay log files are deleted, even if they have not been completely executed by the slave SQL thread. (This is a condition likely to exist on a replication slave if you have issued a STOP SLAVE statement or if the slave is highly loaded.) In MySQL 5.5 (unlike the case in MySQL 5.1 and earlier), RESET SLAVE does not change any replication connection parameters such as master host, master port, master user, or master password, which are retained in memory. This means that START SLAVE can be issued without requiring a CHANGE MASTER TO statement following RESET SLAVE. In MySQL 5.5.16 and later, you can use RESET SLAVE ALL to reset these connection parameters (Bug #11809016). Connection parameters are also reset if the slave mysqld is shut down. If the slave SQL thread was in the middle of replicating temporary tables when it was stopped, and RESET SLAVE is issued, these replicated temporary tables are deleted on the slave. URL: http://dev.mysql.com/doc/refman/5.5/en/reset-slave.html 7http://dev.mysql.com/doc/refman/5.5/en/reset-slave.htmlL'SHOW BINARY LOGSSyntax: SHOW BINARY LOGS SHOW MASTER LOGS Lists the binary log files on the server. This statement is used as part of the procedure described in [HELP PURGE BINARY LOGS], that shows how to determine which logs can be purged. mysql> SHOW BINARY LOGS; +---------------+-----------+ | Log_name | File_size | +---------------+-----------+ | binlog.000015 | 724935 | | binlog.000016 | 733481 | +---------------+-----------+ URL: http://dev.mysql.com/doc/refman/5.5/en/show-binary-logs.html <http://dev.mysql.com/doc/refman/5.5/en/show-binary-logs.html(POLYGONKPolygon(ls1,ls2,...) Constructs a Polygon value from a number of LineString or WKB LineString arguments. If any argument does not represent a LinearRing (that is, not a closed and simple LineString), the return value is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions%)MINUTESyntax: MINUTE(time) Returns the minute for time, in the range 0 to 59. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html :mysql> SELECT MINUTE('2008-02-03 10:05:03'); -> 5 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html*DAYSyntax: DAY(date) DAY() is a synonym for DAYOFMONTH(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html+MID%Syntax: MID(str,pos,len) MID(str,pos,len) is a synonym for SUBSTRING(str,pos,len). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html,UUIDSyntax: UUID() Returns a Universal Unique Identifier (UUID) generated according to "DCE 1.1: Remote Procedure Call" (Appendix A) CAE (Common Applications Environment) Specifications published by The Open Group in October 1997 (Document Number C706, http://www.opengroup.org/public/pubs/catalog/c706.htm). A UUID is designed as a number that is globally unique in space and time. Two calls to UUID() are expected to generate two different values, even if these calls are performed on two separate computers that are not connected to each other. A UUID is a 128-bit number represented by a utf8 string of five hexadecimal numbers in aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee format: o The first three numbers are generated from a timestamp. o The fourth number preserves temporal uniqueness in case the timestamp value loses monotonicity (for example, due to daylight saving time). o The fifth number is an IEEE 802 node number that provides spatial uniqueness. A random number is substituted if the latter is not available (for example, because the host computer has no Ethernet card, or we do not know how to find the hardware address of an interface on your operating system). In this case, spatial uniqueness cannot be guaranteed. Nevertheless, a collision should have very low probability. Currently, the MAC address of an interface is taken into account only on FreeBSD and Linux. On other operating systems, MySQL uses a randomly generated 48-bit number. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Hmysql> SELECT UUID(); -> '6ccd780c-baba-1026-9564-0040f4311e29' Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html- LINESTRINGLineString(pt1,pt2,...) Constructs a LineString value from a number of Point or WKB Point arguments. If the number of arguments is less than two, the return value is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functionsz.SLEEP&Syntax: SLEEP(duration) Sleeps (pauses) for the number of seconds given by the duration argument, then returns 0. If SLEEP() is interrupted, it returns 1. The duration may have a fractional part given in microseconds. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html/ CONNECTION_IDSyntax: CONNECTION_ID() Returns the connection ID (thread ID) for the connection. Every connection has an ID that is unique among the set of currently connected clients. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html 0mysql> SELECT CONNECTION_ID(); -> 23786 Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html0DELETESyntax: Single-table syntax: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] Multiple-table syntax: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] tbl_name[.*] [, tbl_name[.*]] ... FROM table_references [WHERE where_condition] Or: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name[.*] [, tbl_name[.*]] ... USING table_references [WHERE where_condition] For the single-table syntax, the DELETE statement deletes rows from tbl_name and returns a count of the number of deleted rows. This count can be obtained by calling the ROW_COUNT() function (see http://dev.mysql.com/doc/refman/5.5/en/information-functions.html). The WHERE clause, if given, specifies the conditions that identify which rows to delete. With no WHERE clause, all rows are deleted. If the ORDER BY clause is specified, the rows are deleted in the order that is specified. The LIMIT clause places a limit on the number of rows that can be deleted. For the multiple-table syntax, DELETE deletes from each tbl_name the rows that satisfy the conditions. In this case, ORDER BY and LIMIT cannot be used. where_condition is an expression that evaluates to true for each row to be deleted. It is specified as described in http://dev.mysql.com/doc/refman/5.5/en/select.html. Currently, you cannot delete from a table and select from the same table in a subquery. You need the DELETE privilege on a table to delete rows from it. You need only the SELECT privilege for any columns that are only read, such as those named in the WHERE clause. As stated, a DELETE statement with no WHERE clause deletes all rows. A faster way to do this, when you do not need to know the number of deleted rows, is to use TRUNCATE TABLE. However, within a transaction or if you have a lock on the table, TRUNCATE TABLE cannot be used whereas DELETE can. See [HELP TRUNCATE TABLE], and [HELP LOCK]. URL: http://dev.mysql.com/doc/refman/5.5/en/delete.html 2http://dev.mysql.com/doc/refman/5.5/en/delete.html1ROUNDHSyntax: ROUND(X), ROUND(X,D) Rounds the argument X to D decimal places. The rounding algorithm depends on the data type of X. D defaults to 0 if not specified. D can be negative to cause D digits left of the decimal point of the value X to become zero. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT ROUND(-1.23); -> -1 mysql> SELECT ROUND(-1.58); -> -2 mysql> SELECT ROUND(1.58); -> 2 mysql> SELECT ROUND(1.298, 1); -> 1.3 mysql> SELECT ROUND(1.298, 0); -> 1 mysql> SELECT ROUND(23.298, -1); -> 20 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html2NULLIFSyntax: NULLIF(expr1,expr2) Returns NULL if expr1 = expr2 is true, otherwise returns expr1. This is the same as CASE WHEN expr1 = expr2 THEN NULL ELSE expr1 END. URL: http://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html Smysql> SELECT NULLIF(1,1); -> NULL mysql> SELECT NULLIF(1,2); -> 1 Bhttp://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html3CLOSEiSyntax: CLOSE cursor_name This statement closes a previously opened cursor. For an example, see http://dev.mysql.com/doc/refman/5.5/en/cursors.html. An error occurs if the cursor is not open. If not closed explicitly, a cursor is closed at the end of the BEGIN ... END block in which it was declared. URL: http://dev.mysql.com/doc/refman/5.5/en/close.html 1http://dev.mysql.com/doc/refman/5.5/en/close.html4 STOP SLAVESyntax: STOP SLAVE [thread_types] thread_types: [thread_type [, thread_type] ... ] thread_type: IO_THREAD | SQL_THREAD Stops the slave threads. STOP SLAVE requires the SUPER privilege. Recommended best practice is to execute STOP SLAVE on the slave before stopping the slave server (see http://dev.mysql.com/doc/refman/5.5/en/server-shutdown.html, for more information). When using the row-based logging format: You should execute STOP SLAVE on the slave prior to shutting down the slave server if you are replicating any tables that use a nontransactional storage engine (see the Note later in this section). In MySQL 5.5.9 and later, you can also use STOP SLAVE SQL_THREAD for this purpose. Like START SLAVE, this statement may be used with the IO_THREAD and SQL_THREAD options to name the thread or threads to be stopped. *Note*: In MySQL 5.5, STOP SLAVE waits until the current replication event group affecting one or more non-transactional tables has finished executing (if there is any such replication group), or until the user issues a KILL QUERY or KILL CONNECTION statement. (Bug #319, Bug #38205) URL: http://dev.mysql.com/doc/refman/5.5/en/stop-slave.html 6http://dev.mysql.com/doc/refman/5.5/en/stop-slave.html/5TIMEDIFFSyntax: TIMEDIFF(expr1,expr2) TIMEDIFF() returns expr1 - expr2 expressed as a time value. expr1 and expr2 are time or date-and-time expressions, but both must be of the same type. The result returned by TIMEDIFF() is limited to the range allowed for TIME values. Alternatively, you can use either of the functions TIMESTAMPDIFF() and UNIX_TIMESTAMP(), both of which return integers. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT TIMEDIFF('2000:01:01 00:00:00', -> '2000:01:01 00:00:00.000001'); -> '-00:00:00.000001' mysql> SELECT TIMEDIFF('2008-12-31 23:59:59.000001', -> '2008-12-30 01:01:01.000002'); -> '46:58:57.999999' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html6REPLACE FUNCTION%Syntax: REPLACE(str,from_str,to_str) Returns the string str with all occurrences of the string from_str replaced by the string to_str. REPLACE() performs a case-sensitive match when searching for from_str. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html Qmysql> SELECT REPLACE('www.mysql.com', 'w', 'Ww'); -> 'WwWwWw.mysql.com' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html7USESyntax: USE db_name The USE db_name statement tells MySQL to use the db_name database as the default (current) database for subsequent statements. The database remains the default until the end of the session or another USE statement is issued: USE db1; SELECT COUNT(*) FROM mytable; # selects from db1.mytable USE db2; SELECT COUNT(*) FROM mytable; # selects from db2.mytable URL: http://dev.mysql.com/doc/refman/5.5/en/use.html /http://dev.mysql.com/doc/refman/5.5/en/use.htmlI8 LINEFROMTEXTLineFromText(wkt[,srid]), LineStringFromText(wkt[,srid]) Constructs a LINESTRING value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functionsu9 CASE OPERATORSyntax: CASE value WHEN [compare_value] THEN result [WHEN [compare_value] THEN result ...] [ELSE result] END CASE WHEN [condition] THEN result [WHEN [condition] THEN result ...] [ELSE result] END The first version returns the result where value=compare_value. The second version returns the result for the first condition that is true. If there was no matching result value, the result after ELSE is returned, or NULL if there is no ELSE part. URL: http://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html mysql> SELECT CASE 1 WHEN 1 THEN 'one' -> WHEN 2 THEN 'two' ELSE 'more' END; -> 'one' mysql> SELECT CASE WHEN 1>0 THEN 'true' ELSE 'false' END; -> 'true' mysql> SELECT CASE BINARY 'B' -> WHEN 'a' THEN 1 WHEN 'b' THEN 2 END; -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html:SHOW MASTER STATUSVSyntax: SHOW MASTER STATUS This statement provides status information about the binary log files of the master. It requires either the SUPER or REPLICATION CLIENT privilege. Example: mysql> SHOW MASTER STATUS; +---------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +---------------+----------+--------------+------------------+ | mysql-bin.003 | 73 | test | manual,mysql | +---------------+----------+--------------+------------------+ URL: http://dev.mysql.com/doc/refman/5.5/en/show-master-status.html >http://dev.mysql.com/doc/refman/5.5/en/show-master-status.html;ADDTIMESyntax: ADDTIME(expr1,expr2) ADDTIME() adds expr2 to expr1 and returns the result. expr1 is a time or datetime expression, and expr2 is a time expression. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT ADDTIME('2007-12-31 23:59:59.999999', '1 1:1:1.000002'); -> '2008-01-02 01:01:01.000001' mysql> SELECT ADDTIME('01:00:00.999999', '02:00:00.999998'); -> '03:00:01.999997' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html[<SPATIAL"For MyISAM tables, MySQL can create spatial indexes using syntax similar to that for creating regular indexes, but extended with the SPATIAL keyword. Currently, columns in spatial indexes must be declared NOT NULL. The following examples demonstrate how to create spatial indexes: o With CREATE TABLE: CREATE TABLE geom (g GEOMETRY NOT NULL, SPATIAL INDEX(g)) ENGINE=MyISAM; o With ALTER TABLE: ALTER TABLE geom ADD SPATIAL INDEX(g); o With CREATE INDEX: CREATE SPATIAL INDEX sp_index ON geom (g); For MyISAM tables, SPATIAL INDEX creates an R-tree index. For storage engines that support nonspatial indexing of spatial columns, the engine creates a B-tree index. A B-tree index on spatial values will be useful for exact-value lookups, but not for range scans. For more information on indexing spatial columns, see [HELP CREATE INDEX]. To drop spatial indexes, use ALTER TABLE or DROP INDEX: o With ALTER TABLE: ALTER TABLE geom DROP INDEX g; o With DROP INDEX: DROP INDEX sp_index ON geom; Example: Suppose that a table geom contains more than 32,000 geometries, which are stored in the column g of type GEOMETRY. The table also has an AUTO_INCREMENT column fid for storing object ID values. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-indexes.html Dhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-indexes.htmlH= TO_SECONDSSyntax: TO_SECONDS(expr) Given a date or datetime expr, returns a the number of seconds since the year 0. If expr is not a valid date or datetime value, returns NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT TO_SECONDS(950501); -> 62966505600 mysql> SELECT TO_SECONDS('2009-11-29'); -> 63426672000 mysql> SELECT TO_SECONDS('2009-11-29 13:43:32'); -> 63426721412 mysql> SELECT TO_SECONDS( NOW() ); -> 63426721458 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html> TIMESTAMPDIFF5Syntax: TIMESTAMPDIFF(unit,datetime_expr1,datetime_expr2) Returns datetime_expr2 - datetime_expr1, where datetime_expr1 and datetime_expr2 are date or datetime expressions. One expression may be a date and the other a datetime; a date value is treated as a datetime having the time part '00:00:00' where necessary. The unit for the result (an integer) is given by the unit argument. The legal values for unit are the same as those listed in the description of the TIMESTAMPADD() function. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT TIMESTAMPDIFF(MONTH,'2003-02-01','2003-05-01'); -> 3 mysql> SELECT TIMESTAMPDIFF(YEAR,'2002-05-01','2001-01-01'); -> -1 mysql> SELECT TIMESTAMPDIFF(MINUTE,'2003-02-01','2003-05-01 12:05:55'); -> 128885 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlU?UPPER%Syntax: UPPER(str) Returns the string str with all characters changed to uppercase according to the current character set mapping. The default is latin1 (cp1252 West European). mysql> SELECT UPPER('Hej'); -> 'HEJ' See the description of LOWER() for information that also applies to UPPER(), such as information about how to perform lettercase conversion of binary strings (BINARY, VARBINARY, BLOB) for which these functions are ineffective. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html@ FROM_UNIXTIMESyntax: FROM_UNIXTIME(unix_timestamp), FROM_UNIXTIME(unix_timestamp,format) Returns a representation of the unix_timestamp argument as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone. unix_timestamp is an internal timestamp value such as is produced by the UNIX_TIMESTAMP() function. If format is given, the result is formatted according to the format string, which is used the same way as listed in the entry for the DATE_FORMAT() function. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html )mysql> SELECT FROM_UNIXTIME(1196440219); -> '2007-11-30 10:30:19' mysql> SELECT FROM_UNIXTIME(1196440219) + 0; -> 20071130103019.000000 mysql> SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(), -> '%Y %D %M %h:%i:%s %x'); -> '2007 30th November 10:30:59 2007' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html[A MEDIUMBLOBMEDIUMBLOB A BLOB column with a maximum length of 16,777,215 (224 - 1) bytes. Each MEDIUMBLOB value is stored using a 3-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlJBSHA2 Syntax: SHA2(str, hash_length) Calculates the SHA-2 family of hash functions (SHA-224, SHA-256, SHA-384, and SHA-512). The first argument is the cleartext string to be hashed. The second argument indicates the desired bit length of the result, which must have a value of 224, 256, 384, 512, or 0 (which is equivalent to 256). If either argument is NULL or the hash length is not one of the permitted values, the return value is NULL. Otherwise, the function result is a hash value containing the desired number of bits. See the notes at the beginning of this section about storing hash values efficiently. As of MySQL 5.5.6, the return value is a nonbinary string in the connection character set. Before 5.5.6, the return value is a binary string; see the notes at the beginning of this section about using the value as a nonbinary string. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html fmysql> SELECT SHA2('abc', 224); -> '23097d223405d8228642a477bda255b32aadbce4bda0b3f7e36c9da7' @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlCIFNULL Syntax: IFNULL(expr1,expr2) If expr1 is not NULL, IFNULL() returns expr1; otherwise it returns expr2. IFNULL() returns a numeric or string value, depending on the context in which it is used. URL: http://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html mysql> SELECT IFNULL(1,0); -> 1 mysql> SELECT IFNULL(NULL,10); -> 10 mysql> SELECT IFNULL(1/0,10); -> 10 mysql> SELECT IFNULL(1/0,'yes'); -> 'yes' Bhttp://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html3DSHOW FUNCTION CODESyntax: SHOW FUNCTION CODE func_name This statement is similar to SHOW PROCEDURE CODE but for stored functions. See [HELP SHOW PROCEDURE CODE]. URL: http://dev.mysql.com/doc/refman/5.5/en/show-function-code.html >http://dev.mysql.com/doc/refman/5.5/en/show-function-code.htmlE SHOW ERRORSSyntax: SHOW ERRORS [LIMIT [offset,] row_count] SHOW COUNT(*) ERRORS This statement is similar to SHOW WARNINGS, except that it displays information only for errors, rather than for errors, warnings, and notes. The LIMIT clause has the same syntax as for the SELECT statement. See http://dev.mysql.com/doc/refman/5.5/en/select.html. The SHOW COUNT(*) ERRORS statement displays the number of errors. You can also retrieve this number from the error_count variable: SHOW COUNT(*) ERRORS; SELECT @@error_count; SHOW ERRORS and error_count apply only to errors, not warnings or notes. In other respects, they are similar to SHOW WARNINGS and warning_count. In particular, SHOW ERRORS cannot display information for more than max_error_count messages, and error_count can exceed the value of max_error_count if the number of errors exceeds max_error_count. URL: http://dev.mysql.com/doc/refman/5.5/en/show-errors.html 7http://dev.mysql.com/doc/refman/5.5/en/show-errors.html FLEAST*Syntax: LEAST(value1,value2,...) With two or more arguments, returns the smallest (minimum-valued) argument. The arguments are compared using the following rules: o If any argument is NULL, the result is NULL. No comparison is needed. o If the return value is used in an INTEGER context or all arguments are integer-valued, they are compared as integers. o If the return value is used in a REAL context or all arguments are real-valued, they are compared as reals. o If the arguments comprise a mix of numbers and strings, they are compared as numbers. o If any argument is a nonbinary (character) string, the arguments are compared as nonbinary strings. o In all other cases, the arguments are compared as binary strings. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT LEAST(2,0); -> 0 mysql> SELECT LEAST(34.0,3.0,5.0,767.0); -> 3.0 mysql> SELECT LEAST('B','A','C'); -> 'A' @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html]G=R= Equal: URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT 1 = 0; -> 0 mysql> SELECT '0' = 0; -> 1 mysql> SELECT '0.0' = 0; -> 1 mysql> SELECT '0.01' = 0; -> 0 mysql> SELECT '.01' = 0.01; -> 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlHREVERSE%Syntax: REVERSE(str) Returns the string str with the order of the characters reversed. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html /mysql> SELECT REVERSE('abc'); -> 'cba' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html?IISNULLSyntax: ISNULL(expr) If expr is NULL, ISNULL() returns 1, otherwise it returns 0. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html Pmysql> SELECT ISNULL(1+1); -> 0 mysql> SELECT ISNULL(1/0); -> 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlCJBINARYBINARY(M) The BINARY type is similar to the CHAR type, but stores binary byte strings rather than nonbinary character strings. M represents the column length in bytes. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html>KBLOB DATA TYPEA BLOB is a binary large object that can hold a variable amount of data. The four BLOB types are TINYBLOB, BLOB, MEDIUMBLOB, and LONGBLOB. These differ only in the maximum length of the values they can hold. The four TEXT types are TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT. These correspond to the four BLOB types and have the same maximum lengths and storage requirements. See http://dev.mysql.com/doc/refman/5.5/en/storage-requirements.html. URL: http://dev.mysql.com/doc/refman/5.5/en/blob.html 0http://dev.mysql.com/doc/refman/5.5/en/blob.html]LBOUNDARY$Boundary(g) Returns a geometry that is the closure of the combinatorial boundary of the geometry value g. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions M CREATE USER Syntax: CREATE USER user_specification [, user_specification] ... user_specification: user [ IDENTIFIED BY [PASSWORD] 'password' | IDENTIFIED WITH auth_plugin [AS 'auth_string'] ] The CREATE USER statement creates new MySQL accounts. To use it, you must have the global CREATE USER privilege or the INSERT privilege for the mysql database. For each account, CREATE USER creates a new row in the mysql.user table and assigns the account no privileges. An error occurs if the account already exists. Each account name uses the format described in http://dev.mysql.com/doc/refman/5.5/en/account-names.html. For example: CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'mypass'; If you specify only the user name part of the account name, a host name part of '%' is used. The user specification may indicate how the user should authenticate when connecting to the server: o To enable the user to connect with no password (which is insecure), include no IDENTIFIED BY clause: CREATE USER 'jeffrey'@'localhost'; In this case, the account uses built-in authentication and clients must provide no password. o To assign a password, use IDENTIFIED BY with the literal plaintext password value: CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'mypass'; The account uses built-in authentication and clients must match the given password. o To avoid specifying the plaintext password if you know its hash value (the value that PASSWORD() would return for the password), specify the hash value preceded by the keyword PASSWORD: CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY PASSWORD '*90E462C37378CED12064BB3388827D2BA3A9B689'; The account uses built-in authentication and clients must match the given password. o To authenticate the account using a specific authentication plugin, use IDENTIFIED WITH, where auth_plugin is the plugin name. It can be an unquoted name or a quoted string literal. 'auth_string' is an optional quoted string literal to pass to the plugin. The plugin interprets the meaning of the string, so its format is plugin specific. Consult the documentation for a given plugin for information about the authentication string values it accepts. CREATE USER 'jeffrey'@'localhost' IDENTIFIED WITH my_auth_plugin; For connections that use this account, the server invokes the named plugin and clients must provide credentials as required for the authentication method that the plugin implements. If the server cannot find the plugin, either at account-creation time or connect time, an error occurs. IDENTIFIED WITH can be used as of MySQL 5.5.7. The IDENTIFIED BY and IDENTIFIED WITH clauses are mutually exclusive, so at most one of them can be specified for a given user. For additional information about setting passwords, see http://dev.mysql.com/doc/refman/5.5/en/assigning-passwords.html. URL: http://dev.mysql.com/doc/refman/5.5/en/create-user.html 7http://dev.mysql.com/doc/refman/5.5/en/create-user.htmlNPOINTPoint(x,y) Constructs a Point using its coordinates. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functionsO CURRENT_USERSyntax: CURRENT_USER, CURRENT_USER() Returns the user name and host name combination for the MySQL account that the server used to authenticate the current client. This account determines your access privileges. The return value is a string in the utf8 character set. The value of CURRENT_USER() can differ from the value of USER(). URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html mysql> SELECT USER(); -> 'davida@localhost' mysql> SELECT * FROM mysql.user; ERROR 1044: Access denied for user ''@'localhost' to database 'mysql' mysql> SELECT CURRENT_USER(); -> '@localhost' Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.htmlPLCASE%zSyntax: LCASE(str) LCASE() is a synonym for LOWER(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlQ<=hSyntax: <= Less than or equal: URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html %mysql> SELECT 0.1 <= 2; -> 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlR SHOW PROFILES?Syntax: SHOW PROFILES The SHOW PROFILES statement, together with SHOW PROFILE, displays profiling information that indicates resource usage for statements executed during the course of the current session. For more information, see [HELP SHOW PROFILE]. URL: http://dev.mysql.com/doc/refman/5.5/en/show-profiles.html 9http://dev.mysql.com/doc/refman/5.5/en/show-profiles.html >SUPDATESyntax: Single-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] table_reference SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ... [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] Multiple-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] table_references SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ... [WHERE where_condition] For the single-table syntax, the UPDATE statement updates columns of existing rows in the named table with new values. The SET clause indicates which columns to modify and the values they should be given. Each value can be given as an expression, or the keyword DEFAULT to set a column explicitly to its default value. The WHERE clause, if given, specifies the conditions that identify which rows to update. With no WHERE clause, all rows are updated. If the ORDER BY clause is specified, the rows are updated in the order that is specified. The LIMIT clause places a limit on the number of rows that can be updated. For the multiple-table syntax, UPDATE updates rows in each table named in table_references that satisfy the conditions. In this case, ORDER BY and LIMIT cannot be used. where_condition is an expression that evaluates to true for each row to be updated. For expression syntax, see http://dev.mysql.com/doc/refman/5.5/en/expressions.html. table_references and where_condition are is specified as described in http://dev.mysql.com/doc/refman/5.5/en/select.html. You need the UPDATE privilege only for columns referenced in an UPDATE that are actually updated. You need only the SELECT privilege for any columns that are read but not modified. The UPDATE statement supports the following modifiers: o With the LOW_PRIORITY keyword, execution of the UPDATE is delayed until no other clients are reading from the table. This affects only storage engines that use only table-level locking (such as MyISAM, MEMORY, and MERGE). o With the IGNORE keyword, the update statement does not abort even if errors occur during the update. Rows for which duplicate-key conflicts occur are not updated. Rows for which columns are updated to values that would cause data conversion errors are updated to the closest valid values instead. URL: http://dev.mysql.com/doc/refman/5.5/en/update.html 2http://dev.mysql.com/doc/refman/5.5/en/update.html*T IS NOT NULLSyntax: IS NOT NULL Tests whether a value is not NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html Qmysql> SELECT 1 IS NOT NULL, 0 IS NOT NULL, NULL IS NOT NULL; -> 1, 1, 0 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlUCASE STATEMENT~Syntax: CASE case_value WHEN when_value THEN statement_list [WHEN when_value THEN statement_list] ... [ELSE statement_list] END CASE Or: CASE WHEN search_condition THEN statement_list [WHEN search_condition THEN statement_list] ... [ELSE statement_list] END CASE The CASE statement for stored programs implements a complex conditional construct. *Note*: There is also a CASE expression, which differs from the CASE statement described here. See http://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html. The CASE statement cannot have an ELSE NULL clause, and it is terminated with END CASE instead of END. For the first syntax, case_value is an expression. This value is compared to the when_value expression in each WHEN clause until one of them is equal. When an equal when_value is found, the corresponding THEN clause statement_list executes. If no when_value is equal, the ELSE clause statement_list executes, if there is one. This syntax cannot be used to test for equality with NULL because NULL = NULL is false. See http://dev.mysql.com/doc/refman/5.5/en/working-with-null.html. For the second syntax, each WHEN clause search_condition expression is evaluated until one is true, at which point its corresponding THEN clause statement_list executes. If no search_condition is equal, the ELSE clause statement_list executes, if there is one. If no when_value or search_condition matches the value tested and the CASE statement contains no ELSE clause, a Case not found for CASE statement error results. Each statement_list consists of one or more SQL statements; an empty statement_list is not permitted. To handle situations where no value is matched by any WHEN clause, use an ELSE containing an empty BEGIN ... END block, as shown in this example. (The indentation used here in the ELSE clause is for purposes of clarity only, and is not otherwise significant.) DELIMITER | CREATE PROCEDURE p() BEGIN DECLARE v INT DEFAULT 1; CASE v WHEN 2 THEN SELECT v; WHEN 3 THEN SELECT 0; ELSE BEGIN END; END CASE; END; | URL: http://dev.mysql.com/doc/refman/5.5/en/case.html 0http://dev.mysql.com/doc/refman/5.5/en/case.html>VEXECUTE STATEMENTSyntax: EXECUTE stmt_name [USING @var_name [, @var_name] ...] After preparing a statement with PREPARE, you execute it with an EXECUTE statement that refers to the prepared statement name. If the prepared statement contains any parameter markers, you must supply a USING clause that lists user variables containing the values to be bound to the parameters. Parameter values can be supplied only by user variables, and the USING clause must name exactly as many variables as the number of parameter markers in the statement. You can execute a given prepared statement multiple times, passing different variables to it or setting the variables to different values before each execution. URL: http://dev.mysql.com/doc/refman/5.5/en/execute.html 3http://dev.mysql.com/doc/refman/5.5/en/execute.htmlW DROP INDEX'Syntax: DROP [ONLINE|OFFLINE] INDEX index_name ON tbl_name DROP INDEX drops the index named index_name from the table tbl_name. This statement is mapped to an ALTER TABLE statement to drop the index. See [HELP ALTER TABLE]. To drop a primary key, the index name is always PRIMARY, which must be specified as a quoted identifier because PRIMARY is a reserved word: DROP INDEX `PRIMARY` ON t; URL: http://dev.mysql.com/doc/refman/5.5/en/drop-index.html 6http://dev.mysql.com/doc/refman/5.5/en/drop-index.html X MATCH AGAINST% Syntax: MATCH (col1,col2,...) AGAINST (expr [search_modifier]) MySQL has support for full-text indexing and searching: o A full-text index in MySQL is an index of type FULLTEXT. o Full-text indexes can be used only with MyISAM tables, and can be created only for CHAR, VARCHAR, or TEXT columns. o A FULLTEXT index definition can be given in the CREATE TABLE statement when a table is created, or added later using ALTER TABLE or CREATE INDEX. o For large data sets, it is much faster to load your data into a table that has no FULLTEXT index and then create the index after that, than to load data into a table that has an existing FULLTEXT index. Full-text searching is performed using MATCH() ... AGAINST syntax. MATCH() takes a comma-separated list that names the columns to be searched. AGAINST takes a string to search for, and an optional modifier that indicates what type of search to perform. The search string must be a literal string, not a variable or a column name. There are three types of full-text searches: o A natural language search interprets the search string as a phrase in natural human language (a phrase in free text). There are no special operators. The stopword list applies. In addition, words that are present in 50% or more of the rows are considered common and do not match. Full-text searches are natural language searches if the IN NATURAL LANGUAGE MODE modifier is given or if no modifier is given. For more information, see http://dev.mysql.com/doc/refman/5.5/en/fulltext-natural-language.html . o A boolean search interprets the search string using the rules of a special query language. The string contains the words to search for. It can also contain operators that specify requirements such that a word must be present or absent in matching rows, or that it should be weighted higher or lower than usual. Common words such as "some" or "then" are stopwords and do not match if present in the search string. The IN BOOLEAN MODE modifier specifies a boolean search. For more information, see http://dev.mysql.com/doc/refman/5.5/en/fulltext-boolean.html. o A query expansion search is a modification of a natural language search. The search string is used to perform a natural language search. Then words from the most relevant rows returned by the search are added to the search string and the search is done again. The query returns the rows from the second search. The IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION or WITH QUERY EXPANSION modifier specifies a query expansion search. For more information, see http://dev.mysql.com/doc/refman/5.5/en/fulltext-query-expansion.html. URL: http://dev.mysql.com/doc/refman/5.5/en/fulltext-search.html mysql> SELECT id, body, MATCH (title,body) AGAINST -> ('Security implications of running MySQL as root' -> IN NATURAL LANGUAGE MODE) AS score -> FROM articles WHERE MATCH (title,body) AGAINST -> ('Security implications of running MySQL as root' -> IN NATURAL LANGUAGE MODE); +----+-------------------------------------+-----------------+ | id | body | score | +----+-------------------------------------+-----------------+ | 4 | 1. Never run mysqld as root. 2. ... | 1.5219271183014 | | 6 | When configured properly, MySQL ... | 1.3114095926285 | +----+-------------------------------------+-----------------+ 2 rows in set (0.00 sec) ;http://dev.mysql.com/doc/refman/5.5/en/fulltext-search.html /Y CREATE EVENT' Syntax: CREATE [DEFINER = { user | CURRENT_USER }] EVENT [IF NOT EXISTS] event_name ON SCHEDULE schedule [ON COMPLETION [NOT] PRESERVE] [ENABLE | DISABLE | DISABLE ON SLAVE] [COMMENT 'comment'] DO event_body; schedule: AT timestamp [+ INTERVAL interval] ... | EVERY interval [STARTS timestamp [+ INTERVAL interval] ...] [ENDS timestamp [+ INTERVAL interval] ...] interval: quantity {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE | WEEK | SECOND | YEAR_MONTH | DAY_HOUR | DAY_MINUTE | DAY_SECOND | HOUR_MINUTE | HOUR_SECOND | MINUTE_SECOND} This statement creates and schedules a new event. The event will not run unless the Event Scheduler is enabled. For information about checking Event Scheduler status and enabling it if necessary, see http://dev.mysql.com/doc/refman/5.5/en/events-configuration.html. CREATE EVENT requires the EVENT privilege for the schema in which the event is to be created. It might also require the SUPER privilege, depending on the DEFINER value, as described later in this section. The minimum requirements for a valid CREATE EVENT statement are as follows: o The keywords CREATE EVENT plus an event name, which uniquely identifies the event in a database schema. o An ON SCHEDULE clause, which determines when and how often the event executes. o A DO clause, which contains the SQL statement to be executed by an event. This is an example of a minimal CREATE EVENT statement: CREATE EVENT myevent ON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 1 HOUR DO UPDATE myschema.mytable SET mycol = mycol + 1; The previous statement creates an event named myevent. This event executes once---one hour following its creation---by running an SQL statement that increments the value of the myschema.mytable table's mycol column by 1. The event_name must be a valid MySQL identifier with a maximum length of 64 characters. Event names are not case sensitive, so you cannot have two events named myevent and MyEvent in the same schema. In general, the rules governing event names are the same as those for names of stored routines. See http://dev.mysql.com/doc/refman/5.5/en/identifiers.html. An event is associated with a schema. If no schema is indicated as part of event_name, the default (current) schema is assumed. To create an event in a specific schema, qualify the event name with a schema using schema_name.event_name syntax. URL: http://dev.mysql.com/doc/refman/5.5/en/create-event.html 8http://dev.mysql.com/doc/refman/5.5/en/create-event.htmlZABS{Syntax: ABS(X) Returns the absolute value of X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Imysql> SELECT ABS(2); -> 2 mysql> SELECT ABS(-32); -> 32 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html@[ POLYFROMWKB PolyFromWKB(wkb[,srid]), PolygonFromWKB(wkb[,srid]) Constructs a POLYGON value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions\NOT LIKE%Syntax: expr NOT LIKE pat [ESCAPE 'escape_char'] This is the same as NOT (expr LIKE pat [ESCAPE 'escape_char']). URL: http://dev.mysql.com/doc/refman/5.5/en/string-comparison-functions.html Ghttp://dev.mysql.com/doc/refman/5.5/en/string-comparison-functions.html]SPACE%Syntax: SPACE(N) Returns a string consisting of N space characters. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html ,mysql> SELECT SPACE(6); -> ' ' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmla^MBR DEFINITIONIts MBR (Minimum Bounding Rectangle), or Envelope. This is the bounding geometry, formed by the minimum and maximum (X,Y) coordinates: URL: http://dev.mysql.com/doc/refman/5.5/en/gis-class-geometry.html :((MINX MINY, MAXX MINY, MAXX MAXY, MINX MAXY, MINX MINY)) >http://dev.mysql.com/doc/refman/5.5/en/gis-class-geometry.html&_GEOMETRYCOLLECTIONGeometryCollection(g1,g2,...) Constructs a GeometryCollection. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions`MAXSyntax: MAX([DISTINCT] expr) Returns the maximum value of expr. MAX() may take a string argument; in such cases, it returns the maximum string value. See http://dev.mysql.com/doc/refman/5.5/en/mysql-indexes.html. The DISTINCT keyword can be used to find the maximum of the distinct values of expr, however, this produces the same result as omitting DISTINCT. MAX() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html }mysql> SELECT student_name, MIN(test_score), MAX(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlaCREATE FUNCTION UDF@Syntax: CREATE [AGGREGATE] FUNCTION function_name RETURNS {STRING|INTEGER|REAL|DECIMAL} SONAME shared_library_name A user-defined function (UDF) is a way to extend MySQL with a new function that works like a native (built-in) MySQL function such as ABS() or CONCAT(). function_name is the name that should be used in SQL statements to invoke the function. The RETURNS clause indicates the type of the function's return value. DECIMAL is a legal value after RETURNS, but currently DECIMAL functions return string values and should be written like STRING functions. shared_library_name is the basename of the shared object file that contains the code that implements the function. The file must be located in the plugin directory. This directory is given by the value of the plugin_dir system variable. For more information, see http://dev.mysql.com/doc/refman/5.5/en/udf-compiling.html. To create a function, you must have the INSERT privilege for the mysql database. This is necessary because CREATE FUNCTION adds a row to the mysql.func system table that records the function's name, type, and shared library name. If you do not have this table, you should run the mysql_upgrade command to create it. See http://dev.mysql.com/doc/refman/5.5/en/mysql-upgrade.html. URL: http://dev.mysql.com/doc/refman/5.5/en/create-function-udf.html ?http://dev.mysql.com/doc/refman/5.5/en/create-function-udf.htmlwb*cSyntax: * Multiplication: URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html mysql> SELECT 3*5; -> 15 mysql> SELECT 18014398509481984*18014398509481984.0; -> 324518553658426726783156020576256.0 mysql> SELECT 18014398509481984*18014398509481984; -> 0 @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.htmlc TIMESTAMPOTIMESTAMP A timestamp. The range is '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC. TIMESTAMP values are stored as the number of seconds since the epoch ('1970-01-01 00:00:00' UTC). A TIMESTAMP cannot represent the value '1970-01-01 00:00:00' because that is equivalent to 0 seconds from the epoch and the value 0 is reserved for representing '0000-00-00 00:00:00', the "zero" TIMESTAMP value. Unless specified otherwise, the first TIMESTAMP column in a table is defined to be automatically set to the date and time of the most recent modification if not explicitly assigned a value. This makes TIMESTAMP useful for recording the timestamp of an INSERT or UPDATE operation. You can also set any TIMESTAMP column to the current date and time by assigning it a NULL value, unless it has been defined with the NULL attribute to permit NULL values. The automatic initialization and updating to the current date and time can be specified using DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses, as described in http://dev.mysql.com/doc/refman/5.5/en/timestamp-initialization.html. *Note*: The TIMESTAMP format that was used prior to MySQL 4.1 is not supported in MySQL 5.5; see MySQL 3.23, 4.0, 4.1 Reference Manual for information regarding the old format. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.htmld DES_DECRYPT Syntax: DES_DECRYPT(crypt_str[,key_str]) Decrypts a string encrypted with DES_ENCRYPT(). If an error occurs, this function returns NULL. This function works only if MySQL has been configured with SSL support. See http://dev.mysql.com/doc/refman/5.5/en/ssl-connections.html. If no key_str argument is given, DES_DECRYPT() examines the first byte of the encrypted string to determine the DES key number that was used to encrypt the original string, and then reads the key from the DES key file to decrypt the message. For this to work, the user must have the SUPER privilege. The key file can be specified with the --des-key-file server option. If you pass this function a key_str argument, that string is used as the key for decrypting the message. If the crypt_str argument does not appear to be an encrypted string, MySQL returns the given crypt_str. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html}e CACHE INDEX/Syntax: CACHE INDEX tbl_index_list [, tbl_index_list] ... [PARTITION (partition_list | ALL)] IN key_cache_name tbl_index_list: tbl_name [[INDEX|KEY] (index_name[, index_name] ...)] partition_list: partition_name[, partition_name][, ...] The CACHE INDEX statement assigns table indexes to a specific key cache. It is used only for MyISAM tables. After the indexes have been assigned, they can be preloaded into the cache if desired with LOAD INDEX INTO CACHE. The following statement assigns indexes from the tables t1, t2, and t3 to the key cache named hot_cache: mysql> CACHE INDEX t1, t2, t3 IN hot_cache; +---------+--------------------+----------+----------+ | Table | Op | Msg_type | Msg_text | +---------+--------------------+----------+----------+ | test.t1 | assign_to_keycache | status | OK | | test.t2 | assign_to_keycache | status | OK | | test.t3 | assign_to_keycache | status | OK | +---------+--------------------+----------+----------+ URL: http://dev.mysql.com/doc/refman/5.5/en/cache-index.html 7http://dev.mysql.com/doc/refman/5.5/en/cache-index.html`fENDPOINT EndPoint(ls) Returns the Point that is the endpoint of the LineString value ls. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functions 'mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(EndPoint(GeomFromText(@ls))); +-------------------------------------+ | AsText(EndPoint(GeomFromText(@ls))) | +-------------------------------------+ | POINT(3 3) | +-------------------------------------+ ehttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functionsgCOMPRESS rSyntax: COMPRESS(string_to_compress) Compresses a string and returns the result as a binary string. This function requires MySQL to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL. The compressed string can be uncompressed with UNCOMPRESS(). URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html mysql> SELECT LENGTH(COMPRESS(REPEAT('a',1000))); -> 21 mysql> SELECT LENGTH(COMPRESS('')); -> 0 mysql> SELECT LENGTH(COMPRESS('a')); -> 13 mysql> SELECT LENGTH(COMPRESS(REPEAT('a',16))); -> 15 @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html%hINSERTSyntax: INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] {VALUES | VALUE} ({expr | DEFAULT},...),(...),... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] Or: INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name SET col_name={expr | DEFAULT}, ... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] Or: INSERT [LOW_PRIORITY | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] SELECT ... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] INSERT inserts new rows into an existing table. The INSERT ... VALUES and INSERT ... SET forms of the statement insert rows based on explicitly specified values. The INSERT ... SELECT form inserts rows selected from another table or tables. INSERT ... SELECT is discussed further in [HELP INSERT SELECT]. URL: http://dev.mysql.com/doc/refman/5.5/en/insert.html 2http://dev.mysql.com/doc/refman/5.5/en/insert.htmliCOUNTSyntax: COUNT(expr) Returns a count of the number of non-NULL values of expr in the rows retrieved by a SELECT statement. The result is a BIGINT value. COUNT() returns 0 if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html mysql> SELECT student.student_name,COUNT(*) -> FROM student,course -> WHERE student.student_id=course.student_id -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html{jHANDLER5Syntax: HANDLER tbl_name OPEN [ [AS] alias] HANDLER tbl_name READ index_name { = | <= | >= | < | > } (value1,value2,...) [ WHERE where_condition ] [LIMIT ... ] HANDLER tbl_name READ index_name { FIRST | NEXT | PREV | LAST } [ WHERE where_condition ] [LIMIT ... ] HANDLER tbl_name READ { FIRST | NEXT } [ WHERE where_condition ] [LIMIT ... ] HANDLER tbl_name CLOSE The HANDLER statement provides direct access to table storage engine interfaces. It is available for MyISAM and InnoDB tables. URL: http://dev.mysql.com/doc/refman/5.5/en/handler.html 3http://dev.mysql.com/doc/refman/5.5/en/handler.htmlUk MLINEFROMTEXTMLineFromText(wkt[,srid]), MultiLineStringFromText(wkt[,srid]) Constructs a MULTILINESTRING value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions^lGEOMCOLLFROMWKB GeomCollFromWKB(wkb[,srid]), GeometryCollectionFromWKB(wkb[,srid]) Constructs a GEOMETRYCOLLECTION value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functionsj2m HELP_DATE WThis help information was generated from the MySQL 5.5 Reference Manual on: 2012-08-25 n RENAME TABLE'ESyntax: RENAME TABLE tbl_name TO new_tbl_name [, tbl_name2 TO new_tbl_name2] ... This statement renames one or more tables. The rename operation is done atomically, which means that no other session can access any of the tables while the rename is running. For example, if you have an existing table old_table, you can create another table new_table that has the same structure but is empty, and then replace the existing table with the empty one as follows (assuming that backup_table does not already exist): URL: http://dev.mysql.com/doc/refman/5.5/en/rename-table.html ^CREATE TABLE new_table (...); RENAME TABLE old_table TO backup_table, new_table TO old_table; 8http://dev.mysql.com/doc/refman/5.5/en/rename-table.htmlOoBOOLEANBOOL, BOOLEAN These types are synonyms for TINYINT(1). A value of zero is considered false. Nonzero values are considered true: mysql> SELECT IF(0, 'true', 'false'); +------------------------+ | IF(0, 'true', 'false') | +------------------------+ | false | +------------------------+ mysql> SELECT IF(1, 'true', 'false'); +------------------------+ | IF(1, 'true', 'false') | +------------------------+ | true | +------------------------+ mysql> SELECT IF(2, 'true', 'false'); +------------------------+ | IF(2, 'true', 'false') | +------------------------+ | true | +------------------------+ However, the values TRUE and FALSE are merely aliases for 1 and 0, respectively, as shown here: mysql> SELECT IF(0 = FALSE, 'true', 'false'); +--------------------------------+ | IF(0 = FALSE, 'true', 'false') | +--------------------------------+ | true | +--------------------------------+ mysql> SELECT IF(1 = TRUE, 'true', 'false'); +-------------------------------+ | IF(1 = TRUE, 'true', 'false') | +-------------------------------+ | true | +-------------------------------+ mysql> SELECT IF(2 = TRUE, 'true', 'false'); +-------------------------------+ | IF(2 = TRUE, 'true', 'false') | +-------------------------------+ | false | +-------------------------------+ mysql> SELECT IF(2 = FALSE, 'true', 'false'); +--------------------------------+ | IF(2 = FALSE, 'true', 'false') | +--------------------------------+ | false | +--------------------------------+ The last two statements display the results shown because 2 is equal to neither 1 nor 0. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlVpDEFAULTSyntax: DEFAULT(col_name) Returns the default value for a table column. An error results if the column has no default value. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html 5mysql> UPDATE t SET i = DEFAULT(i)+1 WHERE id < 100; Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlqMODSyntax: MOD(N,M), N % M, N MOD M Modulo operation. Returns the remainder of N divided by M. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT MOD(234, 10); -> 4 mysql> SELECT 253 % 7; -> 1 mysql> SELECT MOD(29,9); -> 2 mysql> SELECT 29 MOD 9; -> 2 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlrTINYTEXTTINYTEXT [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 255 (28 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. Each TINYTEXT value is stored using a 1-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlJsOPTIMIZE TABLESyntax: OPTIMIZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE tbl_name [, tbl_name] ... OPTIMIZE TABLE should be used if you have deleted a large part of a table or if you have made many changes to a table with variable-length rows (tables that have VARCHAR, VARBINARY, BLOB, or TEXT columns). Deleted rows are maintained in a linked list and subsequent INSERT operations reuse old row positions. You can use OPTIMIZE TABLE to reclaim the unused space and to defragment the data file. After extensive changes to a table, this statement may also improve performance of statements that use the table, sometimes significantly. This statement requires SELECT and INSERT privileges for the table. OPTIMIZE TABLE is supported for partitioned tables, and you can use ALTER TABLE ... OPTIMIZE PARTITION to optimize one or more partitions; for more information, see [HELP ALTER TABLE], and http://dev.mysql.com/doc/refman/5.5/en/partitioning-maintenance.html. URL: http://dev.mysql.com/doc/refman/5.5/en/optimize-table.html :http://dev.mysql.com/doc/refman/5.5/en/optimize-table.html;tDECODE Syntax: DECODE(crypt_str,pass_str) Decrypts the encrypted string crypt_str using pass_str as the password. crypt_str should be a string returned from ENCODE(). URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlu<=>Syntax: <=> NULL-safe equal. This operator performs an equality comparison like the = operator, but returns 1 rather than NULL if both operands are NULL, and 0 rather than NULL if one operand is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT 1 <=> 1, NULL <=> NULL, 1 <=> NULL; -> 1, 1, 0 mysql> SELECT 1 = 1, NULL = NULL, 1 = NULL; -> 1, NULL, NULL @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlHvHELP STATEMENTSyntax: HELP 'search_string' The HELP statement returns online information from the MySQL Reference manual. Its proper operation requires that the help tables in the mysql database be initialized with help topic information (see http://dev.mysql.com/doc/refman/5.5/en/server-side-help-support.html). The HELP statement searches the help tables for the given search string and displays the result of the search. The search string is not case sensitive. URL: http://dev.mysql.com/doc/refman/5.5/en/help.html 0http://dev.mysql.com/doc/refman/5.5/en/help.htmlwRESETSyntax: RESET reset_option [, reset_option] ... The RESET statement is used to clear the state of various server operations. You must have the RELOAD privilege to execute RESET. RESET acts as a stronger version of the FLUSH statement. See [HELP FLUSH]. The RESET statement causes an implicit commit. See http://dev.mysql.com/doc/refman/5.5/en/implicit-commit.html. URL: http://dev.mysql.com/doc/refman/5.5/en/reset.html 1http://dev.mysql.com/doc/refman/5.5/en/reset.htmlnxGET_LOCKSyntax: GET_LOCK(str,timeout) Tries to obtain a lock with a name given by the string str, using a timeout of timeout seconds. Returns 1 if the lock was obtained successfully, 0 if the attempt timed out (for example, because another client has previously locked the name), or NULL if an error occurred (such as running out of memory or the thread was killed with mysqladmin kill). If you have a lock obtained with GET_LOCK(), it is released when you execute RELEASE_LOCK(), execute a new GET_LOCK(), or your connection terminates (either normally or abnormally). Locks obtained with GET_LOCK() do not interact with transactions. That is, committing a transaction does not release any such locks obtained during the transaction. This function can be used to implement application locks or to simulate record locks. Names are locked on a server-wide basis. If a name has been locked by one client, GET_LOCK() blocks any request by another client for a lock with the same name. This enables clients that agree on a given lock name to use the name to perform cooperative advisory locking. But be aware that it also enables a client that is not among the set of cooperating clients to lock a name, either inadvertently or deliberately, and thus prevent any of the cooperating clients from locking that name. One way to reduce the likelihood of this is to use lock names that are database-specific or application-specific. For example, use lock names of the form db_name.str or app_name.str. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html mysql> SELECT GET_LOCK('lock1',10); -> 1 mysql> SELECT IS_FREE_LOCK('lock2'); -> 1 mysql> SELECT GET_LOCK('lock2',10); -> 1 mysql> SELECT RELEASE_LOCK('lock2'); -> 1 mysql> SELECT RELEASE_LOCK('lock1'); -> NULL Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlyUCASE%zSyntax: UCASE(str) UCASE() is a synonym for UPPER(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlazSHOW BINLOG EVENTSSyntax: SHOW BINLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count] Shows the events in the binary log. If you do not specify 'log_name', the first binary log is displayed. URL: http://dev.mysql.com/doc/refman/5.5/en/show-binlog-events.html >http://dev.mysql.com/doc/refman/5.5/en/show-binlog-events.htmlL{ MPOLYFROMWKB MPolyFromWKB(wkb[,srid]), MultiPolygonFromWKB(wkb[,srid]) Constructs a MULTIPOLYGON value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions|ITERATESyntax: ITERATE label ITERATE can appear only within LOOP, REPEAT, and WHILE statements. ITERATE means "start the loop again." URL: http://dev.mysql.com/doc/refman/5.5/en/iterate.html 3http://dev.mysql.com/doc/refman/5.5/en/iterate.html}DOxSyntax: DO expr [, expr] ... DO executes the expressions but does not return any results. In most respects, DO is shorthand for SELECT expr, ..., but has the advantage that it is slightly faster when you do not care about the result. DO is useful primarily with functions that have side effects, such as RELEASE_LOCK(). URL: http://dev.mysql.com/doc/refman/5.5/en/do.html .http://dev.mysql.com/doc/refman/5.5/en/do.html~CURTIME$Syntax: CURTIME() Returns the current time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html emysql> SELECT CURTIME(); -> '23:50:26' mysql> SELECT CURTIME() + 0; -> 235026.000000 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html CHAR_LENGTH%GSyntax: CHAR_LENGTH(str) Returns the length of the string str, measured in characters. A multi-byte character counts as a single character. This means that for a string containing five 2-byte characters, LENGTH() returns 10, whereas CHAR_LENGTH() returns 5. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlBIGINT7BIGINT[(M)] [UNSIGNED] [ZEROFILL] A large integer. The signed range is -9223372036854775808 to 9223372036854775807. The unsigned range is 0 to 18446744073709551615. SERIAL is an alias for BIGINT UNSIGNED NOT NULL AUTO_INCREMENT UNIQUE. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlESETSyntax: SET variable_assignment [, variable_assignment] ... variable_assignment: user_var_name = expr | [GLOBAL | SESSION] system_var_name = expr | [@@global. | @@session. | @@]system_var_name = expr The SET statement assigns values to different types of variables that affect the operation of the server or your client. Older versions of MySQL employed SET OPTION, but this syntax is deprecated in favor of SET without OPTION. URL: http://dev.mysql.com/doc/refman/5.5/en/set-statement.html 9http://dev.mysql.com/doc/refman/5.5/en/set-statement.html LOAD XML9 Syntax: LOAD XML [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name' [REPLACE | IGNORE] INTO TABLE [db_name.]tbl_name [CHARACTER SET charset_name] [ROWS IDENTIFIED BY ''] [IGNORE number {LINES | ROWS}] [(column_or_user_var,...)] [SET col_name = expr,...] The LOAD XML statement reads data from an XML file into a table. The file_name must be given as a literal string. The tagname in the optional ROWS IDENTIFIED BY clause must also be given as a literal string, and must be surrounded by angle brackets (< and >). LOAD XML acts as the complement of running the mysql client in XML output mode (that is, starting the client with the --xml option). To write data from a table to an XML file, use a command such as the following one from the system shell: shell> mysql --xml -e 'SELECT * FROM mytable' > file.xml To read the file back into a table, use LOAD XML INFILE. By default, the element is considered to be the equivalent of a database table row; this can be changed using the ROWS IDENTIFIED BY clause. This statement supports three different XML formats: o Column names as attributes and column values as attribute values: o Column names as tags and column values as the content of these tags: value1 value2 o Column names are the name attributes of tags, and values are the contents of these tags: value1 value2 This is the format used by other MySQL tools, such as mysqldump. All 3 formats can be used in the same XML file; the import routine automatically detects the format for each row and interprets it correctly. Tags are matched based on the tag or attribute name and the column name. The following clauses work essentially the same way for LOAD XML as they do for LOAD DATA: o LOW_PRIORITY or CONCURRENT o LOCAL o REPLACE or IGNORE o CHARACTER SET o (column_or_user_var,...) o SET See [HELP LOAD DATA], for more information about these clauses. The IGNORE number LINES or IGNORE number ROWS clause causes the first number rows in the XML file to be skipped. It is analogous to the LOAD DATA statement's IGNORE ... LINES clause. URL: http://dev.mysql.com/doc/refman/5.5/en/load-xml.html 4http://dev.mysql.com/doc/refman/5.5/en/load-xml.html_CONV?Syntax: CONV(N,from_base,to_base) Converts numbers between different number bases. Returns a string representation of the number N, converted from base from_base to base to_base. Returns NULL if any argument is NULL. The argument N is interpreted as an integer, but may be specified as an integer or a string. The minimum base is 2 and the maximum base is 36. If to_base is a negative number, N is regarded as a signed number. Otherwise, N is treated as unsigned. CONV() works with 64-bit precision. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT CONV('a',16,2); -> '1010' mysql> SELECT CONV('6E',18,8); -> '172' mysql> SELECT CONV(-17,10,-18); -> '-H' mysql> SELECT CONV(10+'10'+'10'+0xa,10,10); -> '40' Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlnDATEDATE A date. The supported range is '1000-01-01' to '9999-12-31'. MySQL displays DATE values in 'YYYY-MM-DD' format, but permits assignment of values to DATE columns using either strings or numbers. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html ASSIGN-VALUESyntax: := Assignment operator. Causes the user variable on the left hand side of the operator to take on the value to its right. The value on the right hand side may be a literal value, another variable storing a value, or any legal expression that yields a scalar value, including the result of a query (provided that this value is a scalar value). You can perform multiple assignments in the same SET statement. You can perform multiple assignments in the same statement- Unlike =, the := operator is never interpreted as a comparison operator. This means you can use := in any valid SQL statement (not just in SET statements) to assign a value to a variable. URL: http://dev.mysql.com/doc/refman/5.5/en/assignment-operators.html Mmysql> SELECT @var1, @var2; -> NULL, NULL mysql> SELECT @var1 := 1, @var2; -> 1, NULL mysql> SELECT @var1, @var2; -> 1, NULL mysql> SELECT @var1, @var2 := @var1; -> 1, 1 mysql> SELECT @var1, @var2; -> 1, 1 mysql> SELECT @var1:=COUNT(*) FROM t1; -> 4 mysql> SELECT @var1; -> 4 @http://dev.mysql.com/doc/refman/5.5/en/assignment-operators.htmlSHOW OPEN TABLESkSyntax: SHOW OPEN TABLES [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW OPEN TABLES lists the non-TEMPORARY tables that are currently open in the table cache. See http://dev.mysql.com/doc/refman/5.5/en/table-cache.html. The FROM clause, if present, restricts the tables shown to those present in the db_name database. The LIKE clause, if present, indicates which table names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show-open-tables.html <http://dev.mysql.com/doc/refman/5.5/en/show-open-tables.htmlEXTRACTSyntax: EXTRACT(unit FROM date) The EXTRACT() function uses the same kinds of unit specifiers as DATE_ADD() or DATE_SUB(), but extracts parts from the date rather than performing date arithmetic. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Fmysql> SELECT EXTRACT(YEAR FROM '2009-07-02'); -> 2009 mysql> SELECT EXTRACT(YEAR_MONTH FROM '2009-07-02 01:02:03'); -> 200907 mysql> SELECT EXTRACT(DAY_MINUTE FROM '2009-07-02 01:02:03'); -> 20102 mysql> SELECT EXTRACT(MICROSECOND -> FROM '2003-01-02 10:30:00.000123'); -> 123 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlENCRYPT DSyntax: ENCRYPT(str[,salt]) Encrypts str using the Unix crypt() system call and returns a binary string. The salt argument must be a string with at least two characters or the result will be NULL. If no salt argument is given, a random value is used. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html ;mysql> SELECT ENCRYPT('hello'); -> 'VxuFAJXVARROc' @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html SHOW STATUSrSyntax: SHOW [GLOBAL | SESSION] STATUS [LIKE 'pattern' | WHERE expr] SHOW STATUS provides server status information. This information also can be obtained using the mysqladmin extended-status command. The LIKE clause, if present, indicates which variable names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. This statement does not require any privilege. It requires only the ability to connect to the server. With a LIKE clause, the statement displays only rows for those variables with names that match the pattern: mysql> SHOW STATUS LIKE 'Key%'; +--------------------+----------+ | Variable_name | Value | +--------------------+----------+ | Key_blocks_used | 14955 | | Key_read_requests | 96854827 | | Key_reads | 162040 | | Key_write_requests | 7589728 | | Key_writes | 3813196 | +--------------------+----------+ With the GLOBAL modifier, SHOW STATUS displays the status values for all connections to MySQL. With SESSION, it displays the status values for the current connection. If no modifier is present, the default is SESSION. LOCAL is a synonym for SESSION. Some status variables have only a global value. For these, you get the same value for both GLOBAL and SESSION. The scope for each status variable is listed at http://dev.mysql.com/doc/refman/5.5/en/server-status-variables.html. Each invocation of the SHOW STATUS statement uses an internal temporary table and increments the global Created_tmp_tables value. URL: http://dev.mysql.com/doc/refman/5.5/en/show-status.html 7http://dev.mysql.com/doc/refman/5.5/en/show-status.html EXTRACTVALUE% Syntax: ExtractValue(xml_frag, xpath_expr) ExtractValue() takes two string arguments, a fragment of XML markup xml_frag and an XPath expression xpath_expr (also known as a locator); it returns the text (CDATA) of the first text node which is a child of the elements or elements matched by the XPath expression. In MySQL 5.5, the XPath expression can contain at most 127 characters. (This limitation is lifted in MySQL 5.6.) Using this function is the equivalent of performing a match using the xpath_expr after appending /text(). In other words, ExtractValue('Sakila', '/a/b') and ExtractValue('Sakila', '/a/b/text()') produce the same result. If multiple matches are found, the content of the first child text node of each matching element is returned (in the order matched) as a single, space-delimited string. If no matching text node is found for the expression (including the implicit /text())---for whatever reason, as long as xpath_expr is valid, and xml_frag consists of elements which are properly nested and closed---an empty string is returned. No distinction is made between a match on an empty element and no match at all. This is by design. If you need to determine whether no matching element was found in xml_frag or such an element was found but contained no child text nodes, you should test the result of an expression that uses the XPath count() function. For example, both of these statements return an empty string, as shown here: mysql> SELECT ExtractValue('', '/a/b'); +-------------------------------------+ | ExtractValue('', '/a/b') | +-------------------------------------+ | | +-------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT ExtractValue('', '/a/b'); +-------------------------------------+ | ExtractValue('', '/a/b') | +-------------------------------------+ | | +-------------------------------------+ 1 row in set (0.00 sec) However, you can determine whether there was actually a matching element using the following: mysql> SELECT ExtractValue('', 'count(/a/b)'); +-------------------------------------+ | ExtractValue('', 'count(/a/b)') | +-------------------------------------+ | 1 | +-------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT ExtractValue('', 'count(/a/b)'); +-------------------------------------+ | ExtractValue('', 'count(/a/b)') | +-------------------------------------+ | 0 | +-------------------------------------+ 1 row in set (0.01 sec) *Important*: ExtractValue() returns only CDATA, and does not return any tags that might be contained within a matching tag, nor any of their content (see the result returned as val1 in the following example). URL: http://dev.mysql.com/doc/refman/5.5/en/xml-functions.html mysql> SELECT -> ExtractValue('cccddd', '/a') AS val1, -> ExtractValue('cccddd', '/a/b') AS val2, -> ExtractValue('cccddd', '//b') AS val3, -> ExtractValue('cccddd', '/b') AS val4, -> ExtractValue('cccdddeee', '//b') AS val5; +------+------+------+------+---------+ | val1 | val2 | val3 | val4 | val5 | +------+------+------+------+---------+ | ccc | ddd | ddd | | ddd eee | +------+------+------+------+---------+ 9http://dev.mysql.com/doc/refman/5.5/en/xml-functions.html OLD_PASSWORD Syntax: OLD_PASSWORD(str) OLD_PASSWORD() was added when the implementation of PASSWORD() was changed in MySQL 4.1 to improve security. OLD_PASSWORD() returns the value of the pre-4.1 implementation of PASSWORD() as a string, and is intended to permit you to reset passwords for any pre-4.1 clients that need to connect to your version 5.5 MySQL server without locking them out. See http://dev.mysql.com/doc/refman/5.5/en/password-hashing.html. As of MySQL 5.5.3, the return value is a nonbinary string in the connection character set. Before 5.5.3, the return value is a binary string. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlFORMAT%Syntax: FORMAT(X,D[,locale]) Formats the number X to a format like '#,###,###.##', rounded to D decimal places, and returns the result as a string. If D is 0, the result has no decimal point or fractional part. The optional third parameter enables a locale to be specified to be used for the result number's decimal point, thousands separator, and grouping between separators. Permissible locale values are the same as the legal values for the lc_time_names system variable (see http://dev.mysql.com/doc/refman/5.5/en/locale-support.html). If no locale is specified, the default is 'en_US'. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT FORMAT(12332.123456, 4); -> '12,332.1235' mysql> SELECT FORMAT(12332.1,4); -> '12,332.1000' mysql> SELECT FORMAT(12332.2,0); -> '12,332' mysql> SELECT FORMAT(12332.2,2,'de_DE'); -> '12.332,20' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlL||GSyntax: OR, || Logical OR. When both operands are non-NULL, the result is 1 if any operand is nonzero, and 0 otherwise. With a NULL operand, the result is 1 if the other operand is nonzero, and NULL otherwise. If both operands are NULL, the result is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html mysql> SELECT 1 || 1; -> 1 mysql> SELECT 1 || 0; -> 1 mysql> SELECT 0 || 0; -> 0 mysql> SELECT 0 || NULL; -> NULL mysql> SELECT 1 || NULL; -> 1 =http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html BIT_LENGTH%Syntax: BIT_LENGTH(str) Returns the length of the string str in bits. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 0mysql> SELECT BIT_LENGTH('text'); -> 32 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html EXTERIORRINGExteriorRing(poly) Returns the exterior ring of the Polygon value poly as a LineString. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functions qmysql> SET @poly = -> 'Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'; mysql> SELECT AsText(ExteriorRing(GeomFromText(@poly))); +-------------------------------------------+ | AsText(ExteriorRing(GeomFromText(@poly))) | +-------------------------------------------+ | LINESTRING(0 0,0 3,3 3,3 0,0 0) | +-------------------------------------------+ bhttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functionsN GEOMFROMWKB GeomFromWKB(wkb[,srid]), GeometryFromWKB(wkb[,srid]) Constructs a geometry value of any type using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functionsaSHOW SLAVE HOSTS Syntax: SHOW SLAVE HOSTS Displays a list of replication slaves currently registered with the master. (Before MySQL 5.5.3, only slaves started with the --report-host=host_name option are visible in this list.) The list is displayed on any server (not just the master server). The output looks like this: mysql> SHOW SLAVE HOSTS; +------------+-----------+------+-----------+ | Server_id | Host | Port | Master_id | +------------+-----------+------+-----------+ | 192168010 | iconnect2 | 3306 | 192168011 | | 1921680101 | athena | 3306 | 192168011 | +------------+-----------+------+-----------+ o Server_id: The unique server ID of the slave server, as configured in the server's option file, or on the command line with --server-id=value. o Host: The host name of the slave server, as configured in the server's option file, or on the command line with --report-host=host_name. Note that this can differ from the machine name as configured in the operating system. o Port: The port the slave server is listening on. In MySQL 5.5.23 and later, a zero in this column means that the slave port (--report-port) was not set. Prior to MySQL 5.5.23, 3306 was used as the default in such cases (Bug #13333431). o Master_id: The unique server ID of the master server that the slave server is replicating from. Some MySQL versions report another variable, Rpl_recovery_rank. This variable was never used, and was removed in MySQL 5.5.3. (Bug #13963) URL: http://dev.mysql.com/doc/refman/5.5/en/show-slave-hosts.html <http://dev.mysql.com/doc/refman/5.5/en/show-slave-hosts.htmlSTART TRANSACTIONSyntax: START TRANSACTION [WITH CONSISTENT SNAPSHOT] BEGIN [WORK] COMMIT [WORK] [AND [NO] CHAIN] [[NO] RELEASE] ROLLBACK [WORK] [AND [NO] CHAIN] [[NO] RELEASE] SET autocommit = {0 | 1} These statements provide control over use of transactions: o START TRANSACTION or BEGIN start a new transaction. o COMMIT commits the current transaction, making its changes permanent. o ROLLBACK rolls back the current transaction, canceling its changes. o SET autocommit disables or enables the default autocommit mode for the current session. By default, MySQL runs with autocommit mode enabled. This means that as soon as you execute a statement that updates (modifies) a table, MySQL stores the update on disk to make it permanent. The change cannot be rolled back. To disable autocommit mode implicitly for a single series of statements, use the START TRANSACTION statement: START TRANSACTION; SELECT @A:=SUM(salary) FROM table1 WHERE type=1; UPDATE table2 SET summary=@A WHERE type=1; COMMIT; With START TRANSACTION, autocommit remains disabled until you end the transaction with COMMIT or ROLLBACK. The autocommit mode then reverts to its previous state. You can also begin a transaction like this: START TRANSACTION WITH CONSISTENT SNAPSHOT; The WITH CONSISTENT SNAPSHOT option starts a consistent read for storage engines that are capable of it. This applies only to InnoDB. The effect is the same as issuing a START TRANSACTION followed by a SELECT from any InnoDB table. See http://dev.mysql.com/doc/refman/5.5/en/innodb-consistent-read.html. The WITH CONSISTENT SNAPSHOT option does not change the current transaction isolation level, so it provides a consistent snapshot only if the current isolation level is one that permits consistent read (REPEATABLE READ or SERIALIZABLE). *Important*: Many APIs used for writing MySQL client applications (such as JDBC) provide their own methods for starting transactions that can (and sometimes should) be used instead of sending a START TRANSACTION statement from the client. See http://dev.mysql.com/doc/refman/5.5/en/connectors-apis.html, or the documentation for your API, for more information. To disable autocommit mode explicitly, use the following statement: SET autocommit=0; After disabling autocommit mode by setting the autocommit variable to zero, changes to transaction-safe tables (such as those for InnoDB or NDBCLUSTER) are not made permanent immediately. You must use COMMIT to store your changes to disk or ROLLBACK to ignore the changes. autocommit is a session variable and must be set for each session. To disable autocommit mode for each new connection, see the description of the autocommit system variable at http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html. BEGIN and BEGIN WORK are supported as aliases of START TRANSACTION for initiating a transaction. START TRANSACTION is standard SQL syntax and is the recommended way to start an ad-hoc transaction. The BEGIN statement differs from the use of the BEGIN keyword that starts a BEGIN ... END compound statement. The latter does not begin a transaction. See [HELP BEGIN END]. *Note*: Within all stored programs (stored procedures and functions, triggers, and events), the parser treats BEGIN [WORK] as the beginning of a BEGIN ... END block. Begin a transaction in this context with START TRANSACTION instead. The optional WORK keyword is supported for COMMIT and ROLLBACK, as are the CHAIN and RELEASE clauses. CHAIN and RELEASE can be used for additional control over transaction completion. The value of the completion_type system variable determines the default completion behavior. See http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html. The AND CHAIN clause causes a new transaction to begin as soon as the current one ends, and the new transaction has the same isolation level as the just-terminated transaction. The RELEASE clause causes the server to disconnect the current client session after terminating the current transaction. Including the NO keyword suppresses CHAIN or RELEASE completion, which can be useful if the completion_type system variable is set to cause chaining or release completion by default. URL: http://dev.mysql.com/doc/refman/5.5/en/commit.html 2http://dev.mysql.com/doc/refman/5.5/en/commit.htmlb BETWEEN ANDSyntax: expr BETWEEN min AND max If expr is greater than or equal to min and expr is less than or equal to max, BETWEEN returns 1, otherwise it returns 0. This is equivalent to the expression (min <= expr AND expr <= max) if all the arguments are of the same type. Otherwise type conversion takes place according to the rules described in http://dev.mysql.com/doc/refman/5.5/en/type-conversion.html, but applied to all the three arguments. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT 2 BETWEEN 1 AND 3, 2 BETWEEN 3 and 1; -> 1, 0 mysql> SELECT 1 BETWEEN 2 AND 3; -> 0 mysql> SELECT 'b' BETWEEN 'a' AND 'c'; -> 1 mysql> SELECT 2 BETWEEN 2 AND '3'; -> 1 mysql> SELECT 2 BETWEEN 2 AND 'x-3'; -> 0 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlO MULTIPOLYGONMultiPolygon(poly1,poly2,...) Constructs a MultiPolygon value from a set of Polygon or WKB Polygon arguments. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions TIME_FORMAT/Syntax: TIME_FORMAT(time,format) This is used like the DATE_FORMAT() function, but the format string may contain format specifiers only for hours, minutes, seconds, and microseconds. Other specifiers produce a NULL value or 0. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Wmysql> SELECT TIME_FORMAT('100:00:00', '%H %k %h %I %l'); -> '100 100 04 04 4' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html:LEFT%Syntax: LEFT(str,len) Returns the leftmost len characters from the string str, or NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 7mysql> SELECT LEFT('foobarbar', 5); -> 'fooba' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlFLUSH QUERY CACHErYou can defragment the query cache to better utilize its memory with the FLUSH QUERY CACHE statement. The statement does not remove any queries from the cache. The RESET QUERY CACHE statement removes all query results from the query cache. The FLUSH TABLES statement also does this. URL: http://dev.mysql.com/doc/refman/5.5/en/query-cache-status-and-maintenance.html Nhttp://dev.mysql.com/doc/refman/5.5/en/query-cache-status-and-maintenance.html SET DATA TYPESET('value1','value2',...) [CHARACTER SET charset_name] [COLLATE collation_name] A set. A string object that can have zero or more values, each of which must be chosen from the list of values 'value1', 'value2', ... A SET column can have a maximum of 64 members. SET values are represented internally as integers. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlRANDSyntax: RAND(), RAND(N) Returns a random floating-point value v in the range 0 <= v < 1.0. If a constant integer argument N is specified, it is used as the seed value, which produces a repeatable sequence of column values. In the following example, note that the sequences of values produced by RAND(3) is the same both places where it occurs. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> CREATE TABLE t (i INT); Query OK, 0 rows affected (0.42 sec) mysql> INSERT INTO t VALUES(1),(2),(3); Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT i, RAND() FROM t; +------+------------------+ | i | RAND() | +------+------------------+ | 1 | 0.61914388706828 | | 2 | 0.93845168309142 | | 3 | 0.83482678498591 | +------+------------------+ 3 rows in set (0.00 sec) mysql> SELECT i, RAND(3) FROM t; +------+------------------+ | i | RAND(3) | +------+------------------+ | 1 | 0.90576975597606 | | 2 | 0.37307905813035 | | 3 | 0.14808605345719 | +------+------------------+ 3 rows in set (0.00 sec) mysql> SELECT i, RAND() FROM t; +------+------------------+ | i | RAND() | +------+------------------+ | 1 | 0.35877890638893 | | 2 | 0.28941420772058 | | 3 | 0.37073435016976 | +------+------------------+ 3 rows in set (0.00 sec) mysql> SELECT i, RAND(3) FROM t; +------+------------------+ | i | RAND(3) | +------+------------------+ | 1 | 0.90576975597606 | | 2 | 0.37307905813035 | | 3 | 0.14808605345719 | +------+------------------+ 3 rows in set (0.01 sec) Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlRPAD% Syntax: RPAD(str,len,padstr) Returns the string str, right-padded with the string padstr to a length of len characters. If str is longer than len, the return value is shortened to len characters. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html bmysql> SELECT RPAD('hi',5,'?'); -> 'hi???' mysql> SELECT RPAD('hi',1,'?'); -> 'h' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlCREATE DATABASE'Syntax: CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name [create_specification] ... create_specification: [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name CREATE DATABASE creates a database with the given name. To use this statement, you need the CREATE privilege for the database. CREATE SCHEMA is a synonym for CREATE DATABASE. URL: http://dev.mysql.com/doc/refman/5.5/en/create-database.html ;http://dev.mysql.com/doc/refman/5.5/en/create-database.htmlDEC/DEC[(M[,D])] [UNSIGNED] [ZEROFILL], NUMERIC[(M[,D])] [UNSIGNED] [ZEROFILL], FIXED[(M[,D])] [UNSIGNED] [ZEROFILL] These types are synonyms for DECIMAL. The FIXED synonym is available for compatibility with other database systems. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlVAR_POP~Syntax: VAR_POP(expr) Returns the population standard variance of expr. It considers rows as the whole population, not as a sample, so it has the number of rows as the denominator. You can also use VARIANCE(), which is equivalent but is not standard SQL. VAR_POP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlELT%Syntax: ELT(N,str1,str2,str3,...) Returns str1 if N = 1, str2 if N = 2, and so on. Returns NULL if N is less than 1 or greater than the number of arguments. ELT() is the complement of FIELD(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT ELT(1, 'ej', 'Heja', 'hej', 'foo'); -> 'ej' mysql> SELECT ELT(4, 'ej', 'Heja', 'hej', 'foo'); -> 'foo' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html& ALTER VIEW'Syntax: ALTER [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}] [DEFINER = { user | CURRENT_USER }] [SQL SECURITY { DEFINER | INVOKER }] VIEW view_name [(column_list)] AS select_statement [WITH [CASCADED | LOCAL] CHECK OPTION] This statement changes the definition of a view, which must exist. The syntax is similar to that for CREATE VIEW and the effect is the same as for CREATE OR REPLACE VIEW. See [HELP CREATE VIEW]. This statement requires the CREATE VIEW and DROP privileges for the view, and some privilege for each column referred to in the SELECT statement. ALTER VIEW is permitted only to the definer or users with the SUPER privilege. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-view.html 6http://dev.mysql.com/doc/refman/5.5/en/alter-view.htmlnSHOW DATABASESSyntax: SHOW {DATABASES | SCHEMAS} [LIKE 'pattern' | WHERE expr] SHOW DATABASES lists the databases on the MySQL server host. SHOW SCHEMAS is a synonym for SHOW DATABASES. The LIKE clause, if present, indicates which database names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. You see only those databases for which you have some kind of privilege, unless you have the global SHOW DATABASES privilege. You can also get this list using the mysqlshow command. If the server was started with the --skip-show-database option, you cannot use this statement at all unless you have the SHOW DATABASES privilege. URL: http://dev.mysql.com/doc/refman/5.5/en/show-databases.html :http://dev.mysql.com/doc/refman/5.5/en/show-databases.html~]Syntax: ~ Invert all bits. URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html #mysql> SELECT 5 & ~1; -> 4 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html|TEXT,TEXT[(M)] [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 65,535 (216 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. Each TEXT value is stored using a 2-byte length prefix that indicates the number of bytes in the value. An optional length M can be given for this type. If this is done, MySQL creates the column as the smallest TEXT type large enough to hold values M characters long. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html CONCAT_WS%Syntax: CONCAT_WS(separator,str1,str2,...) CONCAT_WS() stands for Concatenate With Separator and is a special form of CONCAT(). The first argument is the separator for the rest of the arguments. The separator is added between the strings to be concatenated. The separator can be a string, as can the rest of the arguments. If the separator is NULL, the result is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT CONCAT_WS(',','First name','Second name','Last Name'); -> 'First name,Second name,Last Name' mysql> SELECT CONCAT_WS(',','First name',NULL,'Last Name'); -> 'First name,Last Name' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html ROW_COUNTSyntax: ROW_COUNT() Before MySQL 5.5.5, ROW_COUNT() returns the number of rows changed, deleted, or inserted by the last statement if it was an UPDATE, DELETE, or INSERT. For other statements, the value may not be meaningful. As of MySQL 5.5.5, ROW_COUNT() returns a value as follows: o DDL statements: 0. This applies to statements such as CREATE TABLE or DROP TABLE. o DML statements other than SELECT: The number of affected rows. This applies to statements such as UPDATE, INSERT, or DELETE (as before), but now also to statements such as ALTER TABLE and LOAD DATA INFILE. o SELECT: -1 if the statement returns a result set, or the number of rows "affected" if it does not. For example, for SELECT * FROM t1, ROW_COUNT() returns -1. For SELECT * FROM t1 INTO OUTFILE 'file_name', ROW_COUNT() returns the number of rows written to the file. o SIGNAL statements: 0. For UPDATE statements, the affected-rows value by default is the number of rows actually changed. If you specify the CLIENT_FOUND_ROWS flag to mysql_real_connect() when connecting to mysqld, the affected-rows value is the number of rows "found"; that is, matched by the WHERE clause. For REPLACE statements, the affected-rows value is 2 if the new row replaced an old row, because in this case, one row was inserted after the duplicate was deleted. For INSERT ... ON DUPLICATE KEY UPDATE statements, the affected-rows value is 1 if the row is inserted as a new row and 2 if an existing row is updated. The ROW_COUNT() value is similar to the value from the mysql_affected_rows() C API function and the row count that the mysql client displays following statement execution. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html mysql> INSERT INTO t VALUES(1),(2),(3); Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 3 | +-------------+ 1 row in set (0.00 sec) mysql> DELETE FROM t WHERE i IN(1,2); Query OK, 2 rows affected (0.00 sec) mysql> SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 2 | +-------------+ 1 row in set (0.00 sec) Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html)ASINSyntax: ASIN(X) Returns the arc sine of X, that is, the value whose sine is X. Returns NULL if X is not in the range -1 to 1. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT ASIN(0.2); -> 0.20135792079033 mysql> SELECT ASIN('foo'); +-------------+ | ASIN('foo') | +-------------+ | 0 | +-------------+ 1 row in set, 1 warning (0.00 sec) mysql> SHOW WARNINGS; +---------+------+-----------------------------------------+ | Level | Code | Message | +---------+------+-----------------------------------------+ | Warning | 1292 | Truncated incorrect DOUBLE value: 'foo' | +---------+------+-----------------------------------------+ Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlSIGNSyntax: SIGN(X) Returns the sign of the argument as -1, 0, or 1, depending on whether X is negative, zero, or positive. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html qmysql> SELECT SIGN(-32); -> -1 mysql> SELECT SIGN(0); -> 0 mysql> SELECT SIGN(234); -> 1 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html SEC_TO_TIMETSyntax: SEC_TO_TIME(seconds) Returns the seconds argument, converted to hours, minutes, and seconds, as a TIME value. The range of the result is constrained to that of the TIME data type. A warning occurs if the argument corresponds to a value outside that range. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html lmysql> SELECT SEC_TO_TIME(2378); -> '00:39:38' mysql> SELECT SEC_TO_TIME(2378) + 0; -> 3938 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlFLOATFLOAT[(M,D)] [UNSIGNED] [ZEROFILL] A small (single-precision) floating-point number. Permissible values are -3.402823466E+38 to -1.175494351E-38, 0, and 1.175494351E-38 to 3.402823466E+38. These are the theoretical limits, based on the IEEE standard. The actual range might be slightly smaller depending on your hardware or operating system. M is the total number of digits and D is the number of digits following the decimal point. If M and D are omitted, values are stored to the limits permitted by the hardware. A single-precision floating-point number is accurate to approximately 7 decimal places. UNSIGNED, if specified, disallows negative values. Using FLOAT might give you some unexpected problems because all calculations in MySQL are done with double precision. See http://dev.mysql.com/doc/refman/5.5/en/no-matching-rows.html. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlnLOCATE%xSyntax: LOCATE(substr,str), LOCATE(substr,str,pos) The first syntax returns the position of the first occurrence of substring substr in string str. The second syntax returns the position of the first occurrence of substring substr in string str, starting at position pos. Returns 0 if substr is not in str. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT LOCATE('bar', 'foobarbar'); -> 4 mysql> SELECT LOCATE('xbar', 'foobar'); -> 0 mysql> SELECT LOCATE('bar', 'foobarbar', 5); -> 7 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlD SHOW EVENTSSyntax: SHOW EVENTS [{FROM | IN} schema_name] [LIKE 'pattern' | WHERE expr] This statement displays information about Event Manager events. It requires the EVENT privilege for the database from which the events are to be shown. In its simplest form, SHOW EVENTS lists all of the events in the current schema: mysql> SELECT CURRENT_USER(), SCHEMA(); +----------------+----------+ | CURRENT_USER() | SCHEMA() | +----------------+----------+ | jon@ghidora | myschema | +----------------+----------+ 1 row in set (0.00 sec) mysql> SHOW EVENTS\G *************************** 1. row *************************** Db: myschema Name: e_daily Definer: jon@ghidora Time zone: SYSTEM Type: RECURRING Execute at: NULL Interval value: 10 Interval field: SECOND Starts: 2006-02-09 10:41:23 Ends: NULL Status: ENABLED Originator: 0 character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci To see events for a specific schema, use the FROM clause. For example, to see events for the test schema, use the following statement: SHOW EVENTS FROM test; The LIKE clause, if present, indicates which event names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show-events.html 7http://dev.mysql.com/doc/refman/5.5/en/show-events.htmlCHARSETSyntax: CHARSET(str) Returns the character set of the string argument. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html mysql> SELECT CHARSET('abc'); -> 'latin1' mysql> SELECT CHARSET(CONVERT('abc' USING utf8)); -> 'utf8' mysql> SELECT CHARSET(USER()); -> 'utf8' Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html8SUBDATESyntax: SUBDATE(date,INTERVAL expr unit), SUBDATE(expr,days) When invoked with the INTERVAL form of the second argument, SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD(). mysql> SELECT DATE_SUB('2008-01-02', INTERVAL 31 DAY); -> '2007-12-02' mysql> SELECT SUBDATE('2008-01-02', INTERVAL 31 DAY); -> '2007-12-02' The second form enables the use of an integer value for days. In such cases, it is interpreted as the number of days to be subtracted from the date or datetime expression expr. mysql> SELECT SUBDATE('2008-01-02 12:00:00', 31); -> '2007-12-02 12:00:00' URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html0 DAYOFYEARSyntax: DAYOFYEAR(date) Returns the day of the year for date, in the range 1 to 366. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 5mysql> SELECT DAYOFYEAR('2007-02-03'); -> 34 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlp%#Syntax: N % M, N MOD M Modulo operation. Returns the remainder of N divided by M. For more information, see the description for the MOD() function in http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html. URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.htmlLONGTEXT0LONGTEXT [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 4,294,967,295 or 4GB (232 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. The effective maximum length of LONGTEXT columns also depends on the configured maximum packet size in the client/server protocol and available memory. Each LONGTEXT value is stored using a 4-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlKILLNSyntax: KILL [CONNECTION | QUERY] thread_id Each connection to mysqld runs in a separate thread. You can see which threads are running with the SHOW PROCESSLIST statement and kill a thread with the KILL thread_id statement. KILL permits an optional CONNECTION or QUERY modifier: o KILL CONNECTION is the same as KILL with no modifier: It terminates the connection associated with the given thread_id. o KILL QUERY terminates the statement that the connection is currently executing, but leaves the connection itself intact. If you have the PROCESS privilege, you can see all threads. If you have the SUPER privilege, you can kill all threads and statements. Otherwise, you can see and kill only your own threads and statements. You can also use the mysqladmin processlist and mysqladmin kill commands to examine and kill threads. *Note*: You cannot use KILL with the Embedded MySQL Server library because the embedded server merely runs inside the threads of the host application. It does not create any connection threads of its own. URL: http://dev.mysql.com/doc/refman/5.5/en/kill.html 0http://dev.mysql.com/doc/refman/5.5/en/kill.htmlDISJOINTDisjoint(g1,g2) Returns 1 or 0 to indicate whether g1 is spatially disjoint from (does not intersect) g2. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries1ASTEXTAsText(g), AsWKT(g) Converts a value in internal geometry format to its WKT representation and returns the string result. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-to-convert-geometries-between-formats.html mysql> SET @g = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(GeomFromText(@g)); +--------------------------+ | AsText(GeomFromText(@g)) | +--------------------------+ | LINESTRING(1 1,2 2,3 3) | +--------------------------+ [http://dev.mysql.com/doc/refman/5.5/en/functions-to-convert-geometries-between-formats.htmlLPAD% Syntax: LPAD(str,len,padstr) Returns the string str, left-padded with the string padstr to a length of len characters. If str is longer than len, the return value is shortened to len characters. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html cmysql> SELECT LPAD('hi',4,'??'); -> '??hi' mysql> SELECT LPAD('hi',1,'??'); -> 'h' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlDECLARE CONDITIONSyntax: DECLARE condition_name CONDITION FOR condition_value condition_value: mysql_error_code | SQLSTATE [VALUE] sqlstate_value The DECLARE ... CONDITION statement declares a named error condition, associating a name with a condition that needs specific handling. The name can be referred to in a subsequent DECLARE ... HANDLER statement (see [HELP DECLARE HANDLER]). Condition declarations must appear before cursor or handler declarations. The condition_value for DECLARE ... CONDITION can be a MySQL error code (a number) or an SQLSTATE value (a 5-character string literal). You should not use MySQL error code 0 or SQLSTATE values that begin with '00', because those indicate success rather than an error condition. For a list of MySQL error codes and SQLSTATE values, see http://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html. URL: http://dev.mysql.com/doc/refman/5.5/en/declare-condition.html =http://dev.mysql.com/doc/refman/5.5/en/declare-condition.htmlrOVERLAPSOverlaps(g1,g2) Returns 1 or 0 to indicate whether g1 spatially overlaps g2. The term spatially overlaps is used if two geometries intersect and their intersection results in a geometry of the same dimension but not equal to either of the given geometries. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries!SET GLOBAL SQL_SLAVE_SKIP_COUNTERoSyntax: SET GLOBAL sql_slave_skip_counter = N This statement skips the next N events from the master. This is useful for recovering from replication stops caused by a statement. This statement is valid only when the slave threads are not running. Otherwise, it produces an error. URL: http://dev.mysql.com/doc/refman/5.5/en/set-global-sql-slave-skip-counter.html Mhttp://dev.mysql.com/doc/refman/5.5/en/set-global-sql-slave-skip-counter.html NUMGEOMETRIESNumGeometries(gc) Returns the number of geometries in the GeometryCollection value gc. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#geometrycollection-property-functions 1mysql> SET @gc = 'GeometryCollection(Point(1 1),LineString(2 2, 3 3))'; mysql> SELECT NumGeometries(GeomFromText(@gc)); +----------------------------------+ | NumGeometries(GeomFromText(@gc)) | +----------------------------------+ | 2 | +----------------------------------+ mhttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#geometrycollection-property-functions MONTHNAME.Syntax: MONTHNAME(date) Returns the full name of the month for date. The language used for the name is controlled by the value of the lc_time_names system variable (http://dev.mysql.com/doc/refman/5.5/en/locale-support.html). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html =mysql> SELECT MONTHNAME('2008-02-03'); -> 'February' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html'JCHANGE MASTER TO&Syntax: CHANGE MASTER TO option [, option] ... option: MASTER_BIND = 'interface_name' | MASTER_HOST = 'host_name' | MASTER_USER = 'user_name' | MASTER_PASSWORD = 'password' | MASTER_PORT = port_num | MASTER_CONNECT_RETRY = interval | MASTER_HEARTBEAT_PERIOD = interval | MASTER_LOG_FILE = 'master_log_name' | MASTER_LOG_POS = master_log_pos | RELAY_LOG_FILE = 'relay_log_name' | RELAY_LOG_POS = relay_log_pos | MASTER_SSL = {0|1} | MASTER_SSL_CA = 'ca_file_name' | MASTER_SSL_CAPATH = 'ca_directory_name' | MASTER_SSL_CERT = 'cert_file_name' | MASTER_SSL_KEY = 'key_file_name' | MASTER_SSL_CIPHER = 'cipher_list' | MASTER_SSL_VERIFY_SERVER_CERT = {0|1} | IGNORE_SERVER_IDS = (server_id_list) server_id_list: [server_id [, server_id] ... ] CHANGE MASTER TO changes the parameters that the slave server uses for connecting to the master server, for reading the master binary log, and reading the slave relay log. It also updates the contents of the master.info and relay-log.info files. To use CHANGE MASTER TO, the slave replication threads must be stopped (use STOP SLAVE if necessary). Options not specified retain their value, except as indicated in the following discussion. Thus, in most cases, there is no need to specify options that do not change. For example, if the password to connect to your MySQL master has changed, you just need to issue these statements to tell the slave about the new password: STOP SLAVE; -- if replication was running CHANGE MASTER TO MASTER_PASSWORD='new3cret'; START SLAVE; -- if you want to restart replication MASTER_HOST, MASTER_USER, MASTER_PASSWORD, and MASTER_PORT provide information to the slave about how to connect to its master: o MASTER_HOST and MASTER_PORT are the host name (or IP address) of the master host and its TCP/IP port. *Note*: Replication cannot use Unix socket files. You must be able to connect to the master MySQL server using TCP/IP. If you specify the MASTER_HOST or MASTER_PORT option, the slave assumes that the master server is different from before (even if the option value is the same as its current value.) In this case, the old values for the master binary log file name and position are considered no longer applicable, so if you do not specify MASTER_LOG_FILE and MASTER_LOG_POS in the statement, MASTER_LOG_FILE='' and MASTER_LOG_POS=4 are silently appended to it. Setting MASTER_HOST='' (that is, setting its value explicitly to an empty string) is not the same as not setting MASTER_HOST at all. Beginning with MySQL 5.5, trying to set MASTER_HOST to an empty string fails with an error. Previously, setting MASTER_HOST to an empty string caused START SLAVE subsequently to fail. (Bug #28796) o MASTER_USER and MASTER_PASSWORD are the user name and password of the account to use for connecting to the master. In MySQL 5.5.20 and later, MASTER_USER cannot be made empty; setting MASTER_USER = '' or leaving it unset when setting a value for for MASTER_PASSWORD causes an error (Bug #13427949). Currently, a password used for a replication slave account is effectively limited to 32 characters in length; the password can be longer, but any excess characters are truncated. This is not due to any limit imposed by the MySQL Server generally, but rather is an issue specific to MySQL Replication. (For more information, see Bug #43439.) The text of a running CHANGE MASTER TO statement, including values for MASTER_USER and MASTER_PASSWORD, can be seen in the output of a concurrent SHOW PROCESSLIST statement. The MASTER_SSL_xxx options provide information about using SSL for the connection. They correspond to the --ssl-xxx options described in http://dev.mysql.com/doc/refman/5.5/en/ssl-options.html, and http://dev.mysql.com/doc/refman/5.5/en/replication-solutions-ssl.html. These options can be changed even on slaves that are compiled without SSL support. They are saved to the master.info file, but are ignored if the slave does not have SSL support enabled. MASTER_CONNECT_RETRY specifies how many seconds to wait between connect retries. The default is 60. The number of reconnection attempts is limited by the --master-retry-count server option; for more information, see http://dev.mysql.com/doc/refman/5.5/en/replication-options.html. The MASTER_BIND option is available in MySQL Cluster NDB 7.2 and later, but is not supported in mainline MySQL 5.5. MASTER_BIND is for use on replication slaves having multiple network interfaces, and determines which of the slave's network interfaces is chosen for connecting to the master. MASTER_HEARTBEAT_PERIOD sets the interval in seconds between replication heartbeats. Whenever the master's binary log is updated with an event, the waiting period for the next heartbeat is reset. interval is a decimal value having the range 0 to 4294967 seconds and a resolution in milliseconds; the smallest nonzero value is 0.001. Heartbeats are sent by the master only if there are no unsent events in the binary log file for a period longer than interval. Setting interval to 0 disables heartbeats altogether. The default value for interval is equal to the value of slave_net_timeout divided by 2. Setting @@global.slave_net_timeout to a value less than that of the current heartbeat interval results in a warning being issued. The effect of issuing RESET SLAVE on the heartbeat interval is to reset it to the default value. MASTER_LOG_FILE and MASTER_LOG_POS are the coordinates at which the slave I/O thread should begin reading from the master the next time the thread starts. RELAY_LOG_FILE and RELAY_LOG_POS are the coordinates at which the slave SQL thread should begin reading from the relay log the next time the thread starts. If you specify either of MASTER_LOG_FILE or MASTER_LOG_POS, you cannot specify RELAY_LOG_FILE or RELAY_LOG_POS. If neither of MASTER_LOG_FILE or MASTER_LOG_POS is specified, the slave uses the last coordinates of the slave SQL thread before CHANGE MASTER TO was issued. This ensures that there is no discontinuity in replication, even if the slave SQL thread was late compared to the slave I/O thread, when you merely want to change, say, the password to use. CHANGE MASTER TO deletes all relay log files and starts a new one, unless you specify RELAY_LOG_FILE or RELAY_LOG_POS. In that case, relay log files are kept; the relay_log_purge global variable is set silently to 0. Prior to MySQL 5.5, RELAY_LOG_FILE required an absolute path. In MySQL 5.5, the path can be relative, in which case the path is assumed to be relative to the slave's data directory. (Bug #12190) IGNORE_SERVER_IDS was added in MySQL 5.5. This option takes a comma-separated list of 0 or more server IDs. Events originating from the corresponding servers are ignored, with the exception of log rotation and deletion events, which are still recorded in the relay log. In circular replication, the originating server normally acts as the terminator of its own events, so that they are not applied more than once. Thus, this option is useful in circular replication when one of the servers in the circle is removed. Suppose that you have a circular replication setup with 4 servers, having server IDs 1, 2, 3, and 4, and server 3 fails. When bridging the gap by starting replication from server 2 to server 4, you can include IGNORE_SERVER_IDS = (3) in the CHANGE MASTER TO statement that you issue on server 4 to tell it to use server 2 as its master instead of server 3. Doing so causes it to ignore and not to propagate any statements that originated with the server that is no longer in use. If a CHANGE MASTER TO statement is issued without any IGNORE_SERVER_IDS option, any existing list is preserved; RESET SLAVE also has no effect on the server ID list. To clear the list of ignored servers, it is necessary to use the option with an empty list: CHANGE MASTER TO IGNORE_SERVER_IDS = (); If IGNORE_SERVER_IDS contains the server's own ID and the server was started with the --replicate-same-server-id option enabled, an error results. Also beginning with MySQL 5.5, the master.info file and the output of SHOW SLAVE STATUS are extended to provide the list of servers that are currently ignored. For more information, see http://dev.mysql.com/doc/refman/5.5/en/slave-logs-status.html, and [HELP SHOW SLAVE STATUS]. Beginning with MySQL 5.5.5, invoking CHANGE MASTER TO causes the previous values for MASTER_HOST, MASTER_PORT, MASTER_LOG_FILE, and MASTER_LOG_POS to be written to the error log, along with other information about the slave's state prior to execution. CHANGE MASTER TO is useful for setting up a slave when you have the snapshot of the master and have recorded the master binary log coordinates corresponding to the time of the snapshot. After loading the snapshot into the slave to synchronize it to the slave, you can run CHANGE MASTER TO MASTER_LOG_FILE='log_name', MASTER_LOG_POS=log_pos on the slave to specify the coordinates at which the slave should begin reading the master binary log. The following example changes the master server the slave uses and establishes the master binary log coordinates from which the slave begins reading. This is used when you want to set up the slave to replicate the master: CHANGE MASTER TO MASTER_HOST='master2.mycompany.com', MASTER_USER='replication', MASTER_PASSWORD='bigs3cret', MASTER_PORT=3306, MASTER_LOG_FILE='master2-bin.001', MASTER_LOG_POS=4, MASTER_CONNECT_RETRY=10; The next example shows an operation that is less frequently employed. It is used when the slave has relay log files that you want it to execute again for some reason. To do this, the master need not be reachable. You need only use CHANGE MASTER TO and start the SQL thread (START SLAVE SQL_THREAD): CHANGE MASTER TO RELAY_LOG_FILE='slave-relay-bin.006', RELAY_LOG_POS=4025; URL: http://dev.mysql.com/doc/refman/5.5/en/change-master-to.html <http://dev.mysql.com/doc/refman/5.5/en/change-master-to.htmlw DROP DATABASE'%Syntax: DROP {DATABASE | SCHEMA} [IF EXISTS] db_name DROP DATABASE drops all tables in the database and deletes the database. Be very careful with this statement! To use DROP DATABASE, you need the DROP privilege on the database. DROP SCHEMA is a synonym for DROP DATABASE. *Important*: When a database is dropped, user privileges on the database are not automatically dropped. See [HELP GRANT]. IF EXISTS is used to prevent an error from occurring if the database does not exist. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-database.html 9http://dev.mysql.com/doc/refman/5.5/en/drop-database.htmlMBREQUALMBREqual(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 are the same. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbrvTIMESTAMP FUNCTIONoSyntax: TIMESTAMP(expr), TIMESTAMP(expr1,expr2) With a single argument, this function returns the date or datetime expression expr as a datetime value. With two arguments, it adds the time expression expr2 to the date or datetime expression expr1 and returns the result as a datetime value. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT TIMESTAMP('2003-12-31'); -> '2003-12-31 00:00:00' mysql> SELECT TIMESTAMP('2003-12-31 12:00:00','12:00:00'); -> '2004-01-01 00:00:00' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlPROCEDURE ANALYSE!TSyntax: ANALYSE([max_elements[,max_memory]]) ANALYSE() examines the result from a query and returns an analysis of the results that suggests optimal data types for each column that may help reduce table sizes. To obtain this analysis, append PROCEDURE ANALYSE to the end of a SELECT statement: SELECT ... FROM ... WHERE ... PROCEDURE ANALYSE([max_elements,[max_memory]]) For example: SELECT col1, col2 FROM table1 PROCEDURE ANALYSE(10, 2000); The results show some statistics for the values returned by the query, and propose an optimal data type for the columns. This can be helpful for checking your existing tables, or after importing new data. You may need to try different settings for the arguments so that PROCEDURE ANALYSE() does not suggest the ENUM data type when it is not appropriate. The arguments are optional and are used as follows: o max_elements (default 256) is the maximum number of distinct values that ANALYSE() notices per column. This is used by ANALYSE() to check whether the optimal data type should be of type ENUM; if there are more than max_elements distinct values, then ENUM is not a suggested type. o max_memory (default 8192) is the maximum amount of memory that ANALYSE() should allocate per column while trying to find all distinct values. URL: http://dev.mysql.com/doc/refman/5.5/en/procedure-analyse.html =http://dev.mysql.com/doc/refman/5.5/en/procedure-analyse.html2 HELP_VERSION This help information was generated from the MySQL 5.5 Reference Manual on: 2012-08-25 (revision: 31914) This information applies to MySQL 5.5 through 5.5.29. CHARACTER_LENGTH%Syntax: CHARACTER_LENGTH(str) CHARACTER_LENGTH() is a synonym for CHAR_LENGTH(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html SHOW GRANTS`Syntax: SHOW GRANTS [FOR user] This statement lists the GRANT statement or statements that must be issued to duplicate the privileges that are granted to a MySQL user account. The account is named using the same format as for the GRANT statement; for example, 'jeffrey'@'localhost'. If you specify only the user name part of the account name, a host name part of '%' is used. For additional information about specifying account names, see [HELP GRANT]. mysql> SHOW GRANTS FOR 'root'@'localhost'; +---------------------------------------------------------------------+ | Grants for root@localhost | +---------------------------------------------------------------------+ | GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION | +---------------------------------------------------------------------+ To list the privileges granted to the account that you are using to connect to the server, you can use any of the following statements: SHOW GRANTS; SHOW GRANTS FOR CURRENT_USER; SHOW GRANTS FOR CURRENT_USER(); If SHOW GRANTS FOR CURRENT_USER (or any of the equivalent syntaxes) is used in DEFINER context, such as within a stored procedure that is defined with SQL SECURITY DEFINER), the grants displayed are those of the definer and not the invoker. URL: http://dev.mysql.com/doc/refman/5.5/en/show-grants.html 7http://dev.mysql.com/doc/refman/5.5/en/show-grants.htmlJSHOW PRIVILEGESSyntax: SHOW PRIVILEGES SHOW PRIVILEGES shows the list of system privileges that the MySQL server supports. The exact list of privileges depends on the version of your server. URL: http://dev.mysql.com/doc/refman/5.5/en/show-privileges.html ;http://dev.mysql.com/doc/refman/5.5/en/show-privileges.htmlCREATE TABLESPACE'lSyntax: CREATE TABLESPACE tablespace_name ADD DATAFILE 'file_name' USE LOGFILE GROUP logfile_group [EXTENT_SIZE [=] extent_size] [INITIAL_SIZE [=] initial_size] [AUTOEXTEND_SIZE [=] autoextend_size] [MAX_SIZE [=] max_size] [NODEGROUP [=] nodegroup_id] [WAIT] [COMMENT [=] comment_text] ENGINE [=] engine_name This statement is used to create a tablespace, which can contain one or more data files, providing storage space for tables. One data file is created and added to the tablespace using this statement. Additional data files may be added to the tablespace by using the ALTER TABLESPACE statement (see [HELP ALTER TABLESPACE]). For rules covering the naming of tablespaces, see http://dev.mysql.com/doc/refman/5.5/en/identifiers.html. *Note*: All MySQL Cluster Disk Data objects share the same namespace. This means that each Disk Data object must be uniquely named (and not merely each Disk Data object of a given type). For example, you cannot have a tablespace and a log file group with the same name, or a tablespace and a data file with the same name. A log file group of one or more UNDO log files must be assigned to the tablespace to be created with the USE LOGFILE GROUP clause. logfile_group must be an existing log file group created with CREATE LOGFILE GROUP (see http://dev.mysql.com/doc/refman/5.5/en/create-logfile-group.html). Multiple tablespaces may use the same log file group for UNDO logging. The EXTENT_SIZE sets the size, in bytes, of the extents used by any files belonging to the tablespace. The default value is 1M. The minimum size is 32K, and theoretical maximum is 2G, although the practical maximum size depends on a number of factors. In most cases, changing the extent size does not have any measurable effect on performance, and the default value is recommended for all but the most unusual situations. An extent is a unit of disk space allocation. One extent is filled with as much data as that extent can contain before another extent is used. In theory, up to 65,535 (64K) extents may used per data file; however, the recommended maximum is 32,768 (32K). The recommended maximum size for a single data file is 32G---that is, 32K extents x 1 MB per extent. In addition, once an extent is allocated to a given partition, it cannot be used to store data from a different partition; an extent cannot store data from more than one partition. This means, for example that a tablespace having a single datafile whose INITIAL_SIZE is 256 MB and whose EXTENT_SIZE is 128M has just two extents, and so can be used to store data from at most two different disk data table partitions. You can see how many extents remain free in a given data file by querying the INFORMATION_SCHEMA.FILES table, and so derive an estimate for how much space remains free in the file. For further discussion and examples, see http://dev.mysql.com/doc/refman/5.5/en/files-table.html. The INITIAL_SIZE parameter sets the data file's total size in bytes. Once the file has been created, its size cannot be changed; however, you can add more data files to the tablespace using ALTER TABLESPACE ... ADD DATAFILE. See [HELP ALTER TABLESPACE]. INITIAL_SIZE is optional; its default value is 128M. On 32-bit systems, the maximum supported value for INITIAL_SIZE is 4G. (Bug #29186) When setting EXTENT_SIZE or INITIAL_SIZE (either or both), you may optionally follow the number with a one-letter abbreviation for an order of magnitude, similar to those used in my.cnf. Generally, this is one of the letters M (for megabytes) or G (for gigabytes). INITIAL_SIZE, EXTENT_SIZE, and UNDO_BUFFER_SIZE are subject to rounding as follows: o EXTENT_SIZE and UNDO_BUFFER_SIZE are each rounded up to the nearest whole multiple of 32K. o INITIAL_SIZE is rounded down to the nearest whole multiple of 32K. For data files, INITIAL_SIZE is subject to further rounding; the result just obtained is rounded up to the nearest whole multiple of EXTENT_SIZE (after any rounding). The rounding just described is done explicitly, and a warning is issued by the MySQL Server when any such rounding is performed. The rounded values are also used by the NDB kernel for calculating INFORMATION_SCHEMA.FILES column values and other purposes. However, to avoid an unexpected result, we suggest that you always use whole multiples of 32K in specifying these options. AUTOEXTEND_SIZE, MAX_SIZE, NODEGROUP, WAIT, and COMMENT are parsed but ignored, and so currently have no effect. These options are intended for future expansion. The ENGINE parameter determines the storage engine which uses this tablespace, with engine_name being the name of the storage engine. Currently, engine_name must be one of the values NDB or NDBCLUSTER. When CREATE TABLESPACE is used with ENGINE = NDB, a tablespace and associated data file are created on each Cluster data node. You can verify that the data files were created and obtain information about them by querying the INFORMATION_SCHEMA.FILES table. For example: mysql> SELECT LOGFILE_GROUP_NAME, FILE_NAME, EXTRA -> FROM INFORMATION_SCHEMA.FILES -> WHERE TABLESPACE_NAME = 'newts' AND FILE_TYPE = 'DATAFILE'; +--------------------+-------------+----------------+ | LOGFILE_GROUP_NAME | FILE_NAME | EXTRA | +--------------------+-------------+----------------+ | lg_3 | newdata.dat | CLUSTER_NODE=3 | | lg_3 | newdata.dat | CLUSTER_NODE=4 | +--------------------+-------------+----------------+ 2 rows in set (0.01 sec) (See http://dev.mysql.com/doc/refman/5.5/en/files-table.html.) CREATE TABLESPACE is useful only with Disk Data storage for MySQL Cluster. See http://dev.mysql.com/doc/refman/5.5/en/mysql-cluster-disk-data.html. To drop a primary key, the index name is always PRIMARY, which must be specified as a quoted identifier because PRIMARY is a reserved word: DROP INDEX `PRIMARY` ON t; URL: http://dev.mysql.com/doc/refman/5.5/en/create-tablespace.html =http://dev.mysql.com/doc/refman/5.5/en/create-tablespace.htmlINSERT FUNCTION%Syntax: INSERT(str,pos,len,newstr) Returns the string str, with the substring beginning at position pos and len characters long replaced by the string newstr. Returns the original string if pos is not within the length of the string. Replaces the rest of the string from position pos if len is not within the length of the rest of the string. Returns NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT INSERT('Quadratic', 3, 4, 'What'); -> 'QuWhattic' mysql> SELECT INSERT('Quadratic', -1, 4, 'What'); -> 'Quadratic' mysql> SELECT INSERT('Quadratic', 3, 100, 'What'); -> 'QuWhat' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlCRC323Syntax: CRC32(expr) Computes a cyclic redundancy check value and returns a 32-bit unsigned value. The result is NULL if the argument is NULL. The argument is expected to be a string and (if possible) is treated as one if it is not. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html hmysql> SELECT CRC32('MySQL'); -> 3259397556 mysql> SELECT CRC32('mysql'); -> 2501908538 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlXORSyntax: XOR Logical XOR. Returns NULL if either operand is NULL. For non-NULL operands, evaluates to 1 if an odd number of operands is nonzero, otherwise 0 is returned. URL: http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html mysql> SELECT 1 XOR 1; -> 0 mysql> SELECT 1 XOR 0; -> 1 mysql> SELECT 1 XOR NULL; -> NULL mysql> SELECT 1 XOR 1 XOR 1; -> 1 =http://dev.mysql.com/doc/refman/5.5/en/logical-operators.htmls STARTPOINT StartPoint(ls) Returns the Point that is the start point of the LineString value ls. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functions 3mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(StartPoint(GeomFromText(@ls))); +---------------------------------------+ | AsText(StartPoint(GeomFromText(@ls))) | +---------------------------------------+ | POINT(1 1) | +---------------------------------------+ ehttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functionsGRANT oSyntax: GRANT priv_type [(column_list)] [, priv_type [(column_list)]] ... ON [object_type] priv_level TO user_specification [, user_specification] ... [REQUIRE {NONE | ssl_option [[AND] ssl_option] ...}] [WITH with_option ...] GRANT PROXY ON user_specification TO user_specification [, user_specification] ... [WITH GRANT OPTION] object_type: TABLE | FUNCTION | PROCEDURE priv_level: * | *.* | db_name.* | db_name.tbl_name | tbl_name | db_name.routine_name user_specification: user [ IDENTIFIED BY [PASSWORD] 'password' | IDENTIFIED WITH auth_plugin [AS 'auth_string'] ] ssl_option: SSL | X509 | CIPHER 'cipher' | ISSUER 'issuer' | SUBJECT 'subject' with_option: GRANT OPTION | MAX_QUERIES_PER_HOUR count | MAX_UPDATES_PER_HOUR count | MAX_CONNECTIONS_PER_HOUR count | MAX_USER_CONNECTIONS count The GRANT statement grants privileges to MySQL user accounts. GRANT also serves to specify other account characteristics such as use of secure connections and limits on access to server resources. To use GRANT, you must have the GRANT OPTION privilege, and you must have the privileges that you are granting. Normally, a database administrator first uses CREATE USER to create an account, then GRANT to define its privileges and characteristics. For example: CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'mypass'; GRANT ALL ON db1.* TO 'jeffrey'@'localhost'; GRANT SELECT ON db2.invoice TO 'jeffrey'@'localhost'; GRANT USAGE ON *.* TO 'jeffrey'@'localhost' WITH MAX_QUERIES_PER_HOUR 90; However, if an account named in a GRANT statement does not already exist, GRANT may create it under the conditions described later in the discussion of the NO_AUTO_CREATE_USER SQL mode. The REVOKE statement is related to GRANT and enables administrators to remove account privileges. See [HELP REVOKE]. When successfully executed from the mysql program, GRANT responds with Query OK, 0 rows affected. To determine what privileges result from the operation, use SHOW GRANTS. See [HELP SHOW GRANTS]. URL: http://dev.mysql.com/doc/refman/5.5/en/grant.html 1http://dev.mysql.com/doc/refman/5.5/en/grant.htmlqDECLARE VARIABLESyntax: DECLARE var_name [, var_name] ... type [DEFAULT value] This statement declares local variables within stored programs. To provide a default value for a variable, include a DEFAULT clause. The value can be specified as an expression; it need not be a constant. If the DEFAULT clause is missing, the initial value is NULL. Local variables are treated like stored routine parameters with respect to data type and overflow checking. See [HELP CREATE PROCEDURE]. Variable declarations must appear before cursor or handler declarations. Local variable names are not case sensitive. Permissible characters and quoting rules are the same as for other identifiers, as described in http://dev.mysql.com/doc/refman/5.5/en/identifiers.html. The scope of a local variable is the BEGIN ... END block within which it is declared. The variable can be referred to in blocks nested within the declaring block, except those blocks that declare a variable with the same name. URL: http://dev.mysql.com/doc/refman/5.5/en/declare-local-variable.html Bhttp://dev.mysql.com/doc/refman/5.5/en/declare-local-variable.htmlO MPOLYFROMTEXTMPolyFromText(wkt[,srid]), MultiPolygonFromText(wkt[,srid]) Constructs a MULTIPOLYGON value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions MBRINTERSECTSMBRIntersects(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 intersect. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbrBIT_ORSyntax: BIT_OR(expr) Returns the bitwise OR of all bits in expr. The calculation is performed with 64-bit (BIGINT) precision. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlYEARWEEKTSyntax: YEARWEEK(date), YEARWEEK(date,mode) Returns year and week for a date. The mode argument works exactly like the mode argument to WEEK(). The year in the result may be different from the year in the date argument for the first and the last week of the year. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 8mysql> SELECT YEARWEEK('1987-01-01'); -> 198653 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html NOT BETWEENSyntax: expr NOT BETWEEN min AND max This is the same as NOT (expr BETWEEN min AND max). URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmloIS NOTSyntax: IS NOT boolean_value Tests a value against a boolean value, where boolean_value can be TRUE, FALSE, or UNKNOWN. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html Zmysql> SELECT 1 IS NOT UNKNOWN, 0 IS NOT UNKNOWN, NULL IS NOT UNKNOWN; -> 1, 1, 0 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html[LOG10Syntax: LOG10(X) Returns the base-10 logarithm of X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT LOG10(2); -> 0.30102999566398 mysql> SELECT LOG10(100); -> 2 mysql> SELECT LOG10(-100); -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlbSQRTSyntax: SQRT(X) Returns the square root of a nonnegative number X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT SQRT(4); -> 2 mysql> SELECT SQRT(20); -> 4.4721359549996 mysql> SELECT SQRT(-16); -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html.DECIMALDECIMAL[(M[,D])] [UNSIGNED] [ZEROFILL] A packed "exact" fixed-point number. M is the total number of digits (the precision) and D is the number of digits after the decimal point (the scale). The decimal point and (for negative numbers) the "-" sign are not counted in M. If D is 0, values have no decimal point or fractional part. The maximum number of digits (M) for DECIMAL is 65. The maximum number of supported decimals (D) is 30. If D is omitted, the default is 0. If M is omitted, the default is 10. UNSIGNED, if specified, disallows negative values. All basic calculations (+, -, *, /) with DECIMAL columns are done with a precision of 65 digits. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html CREATE INDEX'Syntax: CREATE [ONLINE|OFFLINE] [UNIQUE|FULLTEXT|SPATIAL] INDEX index_name [index_type] ON tbl_name (index_col_name,...) [index_option] ... index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' CREATE INDEX is mapped to an ALTER TABLE statement to create indexes. See [HELP ALTER TABLE]. CREATE INDEX cannot be used to create a PRIMARY KEY; use ALTER TABLE instead. For more information about indexes, see http://dev.mysql.com/doc/refman/5.5/en/mysql-indexes.html. URL: http://dev.mysql.com/doc/refman/5.5/en/create-index.html 8http://dev.mysql.com/doc/refman/5.5/en/create-index.htmlCREATE FUNCTION'VThe CREATE FUNCTION statement is used to create stored functions and user-defined functions (UDFs): o For information about creating stored functions, see [HELP CREATE PROCEDURE]. o For information about creating user-defined functions, see [HELP CREATE FUNCTION UDF]. URL: http://dev.mysql.com/doc/refman/5.5/en/create-function.html ;http://dev.mysql.com/doc/refman/5.5/en/create-function.html ALTER DATABASE'= Syntax: ALTER {DATABASE | SCHEMA} [db_name] alter_specification ... ALTER {DATABASE | SCHEMA} db_name UPGRADE DATA DIRECTORY NAME alter_specification: [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name ALTER DATABASE enables you to change the overall characteristics of a database. These characteristics are stored in the db.opt file in the database directory. To use ALTER DATABASE, you need the ALTER privilege on the database. ALTER SCHEMA is a synonym for ALTER DATABASE. The database name can be omitted from the first syntax, in which case the statement applies to the default database. National Language Characteristics The CHARACTER SET clause changes the default database character set. The COLLATE clause changes the default database collation. http://dev.mysql.com/doc/refman/5.5/en/charset.html, discusses character set and collation names. You can see what character sets and collations are available using, respectively, the SHOW CHARACTER SET and SHOW COLLATION statements. See [HELP SHOW CHARACTER SET], and [HELP SHOW COLLATION], for more information. If you change the default character set or collation for a database, stored routines that use the database defaults must be dropped and recreated so that they use the new defaults. (In a stored routine, variables with character data types use the database defaults if the character set or collation are not specified explicitly. See [HELP CREATE PROCEDURE].) Upgrading from Versions Older than MySQL 5.1 The syntax that includes the UPGRADE DATA DIRECTORY NAME clause updates the name of the directory associated with the database to use the encoding implemented in MySQL 5.1 for mapping database names to database directory names (see http://dev.mysql.com/doc/refman/5.5/en/identifier-mapping.html). This clause is for use under these conditions: o It is intended when upgrading MySQL to 5.1 or later from older versions. o It is intended to update a database directory name to the current encoding format if the name contains special characters that need encoding. o The statement is used by mysqlcheck (as invoked by mysql_upgrade). For example, if a database in MySQL 5.0 has the name a-b-c, the name contains instances of the - (dash) character. In MySQL 5.0, the database directory is also named a-b-c, which is not necessarily safe for all file systems. In MySQL 5.1 and later, the same database name is encoded as a@002db@002dc to produce a file system-neutral directory name. When a MySQL installation is upgraded to MySQL 5.1 or later from an older version,the server displays a name such as a-b-c (which is in the old format) as #mysql50#a-b-c, and you must refer to the name using the #mysql50# prefix. Use UPGRADE DATA DIRECTORY NAME in this case to explicitly tell the server to re-encode the database directory name to the current encoding format: ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME; After executing this statement, you can refer to the database as a-b-c without the special #mysql50# prefix. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-database.html :http://dev.mysql.com/doc/refman/5.5/en/alter-database.html GEOMETRYNGeometryN(gc,N) Returns the N-th geometry in the GeometryCollection value gc. Geometries are numbered beginning with 1. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#geometrycollection-property-functions Umysql> SET @gc = 'GeometryCollection(Point(1 1),LineString(2 2, 3 3))'; mysql> SELECT AsText(GeometryN(GeomFromText(@gc),1)); +----------------------------------------+ | AsText(GeometryN(GeomFromText(@gc),1)) | +----------------------------------------+ | POINT(1 1) | +----------------------------------------+ mhttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#geometrycollection-property-functions<<|Syntax: << Shifts a longlong (BIGINT) number to the left. URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html #mysql> SELECT 1 << 2; -> 4 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.htmlSHOW TABLE STATUS(Syntax: SHOW TABLE STATUS [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW TABLE STATUS works likes SHOW TABLES, but provides a lot of information about each non-TEMPORARY table. You can also get this list using the mysqlshow --status db_name command. The LIKE clause, if present, indicates which table names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show-table-status.html =http://dev.mysql.com/doc/refman/5.5/en/show-table-status.htmlMD5 ^Syntax: MD5(str) Calculates an MD5 128-bit checksum for the string. The value is returned as a string of 32 hex digits, or NULL if the argument was NULL. The return value can, for example, be used as a hash key. See the notes at the beginning of this section about storing hash values efficiently. As of MySQL 5.5.3, the return value is a nonbinary string in the connection character set. Before 5.5.3, the return value is a binary string; see the notes at the beginning of this section about using the value as a nonbinary string. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html Lmysql> SELECT MD5('testing'); -> 'ae2b1fca515949e5d54fb22b8ed95575' @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html<^Syntax: < Less than: URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html "mysql> SELECT 2 < 2; -> 0 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlUNIX_TIMESTAMPSyntax: UNIX_TIMESTAMP(), UNIX_TIMESTAMP(date) If called with no argument, returns a Unix timestamp (seconds since '1970-01-01 00:00:00' UTC) as an unsigned integer. If UNIX_TIMESTAMP() is called with a date argument, it returns the value of the argument as seconds since '1970-01-01 00:00:00' UTC. date may be a DATE string, a DATETIME string, a TIMESTAMP, or a number in the format YYMMDD or YYYYMMDD. The server interprets date as a value in the current time zone and converts it to an internal value in UTC. Clients can set their time zone as described in http://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT UNIX_TIMESTAMP(); -> 1196440210 mysql> SELECT UNIX_TIMESTAMP('2007-11-30 10:30:19'); -> 1196440219 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html DAYOFMONTHSyntax: DAYOFMONTH(date) Returns the day of the month for date, in the range 1 to 31, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero day part. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 5mysql> SELECT DAYOFMONTH('2007-02-03'); -> 3 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlASCII%Syntax: ASCII(str) Returns the numeric value of the leftmost character of the string str. Returns 0 if str is the empty string. Returns NULL if str is NULL. ASCII() works for 8-bit characters. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html xmysql> SELECT ASCII('2'); -> 50 mysql> SELECT ASCII(2); -> 50 mysql> SELECT ASCII('dx'); -> 100 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlWDIVSyntax: DIV Integer division. Similar to FLOOR(), but is safe with BIGINT values. As of MySQL 5.5.3, if either operand has a noninteger type, the operands are converted to DECIMAL and divided using DECIMAL arithmetic before converting the result to BIGINT. If the result exceeds BIGINT range, an error occurs. Before MySQL 5.5.3, incorrect results may occur for noninteger operands that exceed BIGINT range. URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html $mysql> SELECT 5 DIV 2; -> 2 @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.htmlQ RENAME USER Syntax: RENAME USER old_user TO new_user [, old_user TO new_user] ... The RENAME USER statement renames existing MySQL accounts. To use it, you must have the global CREATE USER privilege or the UPDATE privilege for the mysql database. An error occurs if any old account does not exist or any new account exists. Each account name uses the format described in http://dev.mysql.com/doc/refman/5.5/en/account-names.html. For example: RENAME USER 'jeffrey'@'localhost' TO 'jeff'@'127.0.0.1'; If you specify only the user name part of the account name, a host name part of '%' is used. RENAME USER causes the privileges held by the old user to be those held by the new user. However, RENAME USER does not automatically drop or invalidate databases or objects within them that the old user created. This includes stored programs or views for which the DEFINER attribute names the old user. Attempts to access such objects may produce an error if they execute in definer security context. (For information about security context, see http://dev.mysql.com/doc/refman/5.5/en/stored-programs-security.html.) The privilege changes take effect as indicated in http://dev.mysql.com/doc/refman/5.5/en/privilege-changes.html. URL: http://dev.mysql.com/doc/refman/5.5/en/rename-user.html 7http://dev.mysql.com/doc/refman/5.5/en/rename-user.htmlSHOW SLAVE STATUSfSyntax: SHOW SLAVE STATUS This statement provides status information on essential parameters of the slave threads. It requires either the SUPER or REPLICATION CLIENT privilege. If you issue this statement using the mysql client, you can use a \G statement terminator rather than a semicolon to obtain a more readable vertical layout: mysql> SHOW SLAVE STATUS\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: localhost Master_User: root Master_Port: 3306 Connect_Retry: 3 Master_Log_File: gbichot-bin.005 Read_Master_Log_Pos: 79 Relay_Log_File: gbichot-relay-bin.005 Relay_Log_Pos: 548 Relay_Master_Log_File: gbichot-bin.005 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 79 Relay_Log_Space: 552 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 8 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: 0 Master_Server_Id: 1 URL: http://dev.mysql.com/doc/refman/5.5/en/show-slave-status.html =http://dev.mysql.com/doc/refman/5.5/en/show-slave-status.htmlGEOMETRY"dMySQL provides a standard way of creating spatial columns for geometry types, for example, with CREATE TABLE or ALTER TABLE. Currently, spatial columns are supported for MyISAM, InnoDB, NDB, and ARCHIVE tables. See also the annotations about spatial indexes under [HELP SPATIAL]. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-columns.html CREATE TABLE geom (g GEOMETRY); Dhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-columns.html5 NUMPOINTS NumPoints(ls) Returns the number of Point objects in the LineString value ls. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functions mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT NumPoints(GeomFromText(@ls)); +------------------------------+ | NumPoints(GeomFromText(@ls)) | +------------------------------+ | 3 | +------------------------------+ ehttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functionsALTER LOGFILE GROUP'mSyntax: ALTER LOGFILE GROUP logfile_group ADD UNDOFILE 'file_name' [INITIAL_SIZE [=] size] [WAIT] ENGINE [=] engine_name This statement adds an UNDO file named 'file_name' to an existing log file group logfile_group. An ALTER LOGFILE GROUP statement has one and only one ADD UNDOFILE clause. No DROP UNDOFILE clause is currently supported. *Note*: All MySQL Cluster Disk Data objects share the same namespace. This means that each Disk Data object must be uniquely named (and not merely each Disk Data object of a given type). For example, you cannot have a tablespace and an undo log file with the same name, or an undo log file and a data file with the same name. The optional INITIAL_SIZE parameter sets the UNDO file's initial size in bytes; if not specified, the initial size default to 128M (128 megabytes). You may optionally follow size with a one-letter abbreviation for an order of magnitude, similar to those used in my.cnf. Generally, this is one of the letters M (for megabytes) or G (for gigabytes). On 32-bit systems, the maximum supported value for INITIAL_SIZE is 4G. (Bug #29186) The minimum permitted value for INITIAL_SIZE is 1M. (Bug #29574) *Note*: WAIT is parsed but otherwise ignored. This keyword currently has no effect, and is intended for future expansion. The ENGINE parameter (required) determines the storage engine which is used by this log file group, with engine_name being the name of the storage engine. Currently, the only accepted values for engine_name are "NDBCLUSTER" and "NDB". The two values are equivalent. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-logfile-group.html ?http://dev.mysql.com/doc/refman/5.5/en/alter-logfile-group.html&YSyntax: & Bitwise AND: URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html %mysql> SELECT 29 & 15; -> 13 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.htmlLOCALTIMESTAMPSyntax: LOCALTIMESTAMP, LOCALTIMESTAMP() LOCALTIMESTAMP and LOCALTIMESTAMP() are synonyms for NOW(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html ASSIGN-EQUALrSyntax: = This operator is used to perform value assignments in two cases, described in the next two paragraphs. Within a SET statement, = is treated as an assignment operator that causes the user variable on the left hand side of the operator to take on the value to its right. (In other words, when used in a SET statement, = is treated identically to :=.) The value on the right hand side may be a literal value, another variable storing a value, or any legal expression that yields a scalar value, including the result of a query (provided that this value is a scalar value). You can perform multiple assignments in the same SET statement. In the SET clause of an UPDATE statement, = also acts as an assignment operator; in this case, however, it causes the column named on the left hand side of the operator to assume the value given to the right, provided any WHERE conditions that are part of the UPDATE are met. You can make multiple assignments in the same SET clause of an UPDATE statement. In any other context, = is treated as a comparison operator. URL: http://dev.mysql.com/doc/refman/5.5/en/assignment-operators.html mysql> SELECT @var1, @var2; -> NULL, NULL mysql> SELECT @var1 := 1, @var2; -> 1, NULL mysql> SELECT @var1, @var2; -> 1, NULL mysql> SELECT @var1, @var2 := @var1; -> 1, 1 mysql> SELECT @var1, @var2; -> 1, 1 @http://dev.mysql.com/doc/refman/5.5/en/assignment-operators.htmlCONVERT% Syntax: CONVERT(expr,type), CONVERT(expr USING transcoding_name) The CONVERT() and CAST() functions take an expression of any type and produce a result value of a specified type. The type for the result can be one of the following values: o BINARY[(N)] o CHAR[(N)] o DATE o DATETIME o DECIMAL[(M[,D])] o SIGNED [INTEGER] o TIME o UNSIGNED [INTEGER] BINARY produces a string with the BINARY data type. See http://dev.mysql.com/doc/refman/5.5/en/binary-varbinary.html for a description of how this affects comparisons. If the optional length N is given, BINARY(N) causes the cast to use no more than N bytes of the argument. Values shorter than N bytes are padded with 0x00 bytes to a length of N. CHAR(N) causes the cast to use no more than N characters of the argument. CAST() and CONVERT(... USING ...) are standard SQL syntax. The non-USING form of CONVERT() is ODBC syntax. CONVERT() with USING is used to convert data between different character sets. In MySQL, transcoding names are the same as the corresponding character set names. For example, this statement converts the string 'abc' in the default character set to the corresponding string in the utf8 character set: SELECT CONVERT('abc' USING utf8); URL: http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html ?SELECT enum_col FROM tbl_name ORDER BY CAST(enum_col AS CHAR); :http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html,ADDDATESyntax: ADDDATE(date,INTERVAL expr unit), ADDDATE(expr,days) When invoked with the INTERVAL form of the second argument, ADDDATE() is a synonym for DATE_ADD(). The related function SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD(). mysql> SELECT DATE_ADD('2008-01-02', INTERVAL 31 DAY); -> '2008-02-02' mysql> SELECT ADDDATE('2008-01-02', INTERVAL 31 DAY); -> '2008-02-02' When invoked with the days form of the second argument, MySQL treats it as an integer number of days to be added to expr. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Amysql> SELECT ADDDATE('2008-01-02', 31); -> '2008-02-02' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html REPEAT LOOPSyntax: [begin_label:] REPEAT statement_list UNTIL search_condition END REPEAT [end_label] The statement list within a REPEAT statement is repeated until the search_condition expression is true. Thus, a REPEAT always enters the loop at least once. statement_list consists of one or more statements, each terminated by a semicolon (;) statement delimiter. A REPEAT statement can be labeled. For the rules regarding label use, see [HELP labels]. URL: http://dev.mysql.com/doc/refman/5.5/en/repeat.html mysql> delimiter // mysql> CREATE PROCEDURE dorepeat(p1 INT) -> BEGIN -> SET @x = 0; -> REPEAT -> SET @x = @x + 1; -> UNTIL @x > p1 END REPEAT; -> END -> // Query OK, 0 rows affected (0.00 sec) mysql> CALL dorepeat(1000)// Query OK, 0 rows affected (0.00 sec) mysql> SELECT @x// +------+ | @x | +------+ | 1001 | +------+ 1 row in set (0.00 sec) 2http://dev.mysql.com/doc/refman/5.5/en/repeat.htmlALTER FUNCTION'Syntax: ALTER FUNCTION func_name [characteristic ...] characteristic: COMMENT 'string' | LANGUAGE SQL | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } This statement can be used to change the characteristics of a stored function. More than one change may be specified in an ALTER FUNCTION statement. However, you cannot change the parameters or body of a stored function using this statement; to make such changes, you must drop and re-create the function using DROP FUNCTION and CREATE FUNCTION. You must have the ALTER ROUTINE privilege for the function. (That privilege is granted automatically to the function creator.) If binary logging is enabled, the ALTER FUNCTION statement might also require the SUPER privilege, as described in http://dev.mysql.com/doc/refman/5.5/en/stored-programs-logging.html. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-function.html :http://dev.mysql.com/doc/refman/5.5/en/alter-function.htmlSMALLINTSMALLINT[(M)] [UNSIGNED] [ZEROFILL] A small integer. The signed range is -32768 to 32767. The unsigned range is 0 to 65535. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlDOUBLE PRECISION%DOUBLE PRECISION[(M,D)] [UNSIGNED] [ZEROFILL], REAL[(M,D)] [UNSIGNED] [ZEROFILL] These types are synonyms for DOUBLE. Exception: If the REAL_AS_FLOAT SQL mode is enabled, REAL is a synonym for FLOAT rather than DOUBLE. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html=ORD%Syntax: ORD(str) If the leftmost character of the string str is a multi-byte character, returns the code for that character, calculated from the numeric values of its constituent bytes using this formula: (1st byte code) + (2nd byte code * 256) + (3rd byte code * 2562) ... If the leftmost character is not a multi-byte character, ORD() returns the same value as the ASCII() function. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html &mysql> SELECT ORD('2'); -> 50 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlDEALLOCATE PREPARETSyntax: {DEALLOCATE | DROP} PREPARE stmt_name To deallocate a prepared statement produced with PREPARE, use a DEALLOCATE PREPARE statement that refers to the prepared statement name. Attempting to execute a prepared statement after deallocating it results in an error. URL: http://dev.mysql.com/doc/refman/5.5/en/deallocate-prepare.html >http://dev.mysql.com/doc/refman/5.5/en/deallocate-prepare.html^ENVELOPE$vEnvelope(g) Returns the Minimum Bounding Rectangle (MBR) for the geometry value g. The result is returned as a Polygon value. The polygon is defined by the corner points of the bounding box: POLYGON((MINX MINY, MAXX MINY, MAXX MAXY, MINX MAXY, MINX MINY)) URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions gmysql> SELECT AsText(Envelope(GeomFromText('LineString(1 1,2 2)'))); +-------------------------------------------------------+ | AsText(Envelope(GeomFromText('LineString(1 1,2 2)'))) | +-------------------------------------------------------+ | POLYGON((1 1,2 1,2 2,1 2,1 1)) | +-------------------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions IS_FREE_LOCK>Syntax: IS_FREE_LOCK(str) Checks whether the lock named str is free to use (that is, not locked). Returns 1 if the lock is free (no one is using the lock), 0 if the lock is in use, and NULL if an error occurs (such as an incorrect argument). URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlvTOUCHESTouches(g1,g2) Returns 1 or 0 to indicate whether g1 spatially touches g2. Two geometries spatially touch if the interiors of the geometries do not intersect, but the boundary of one of the geometries intersects either the boundary or the interior of the other. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries INET_ATONZSyntax: INET_ATON(expr) Given the dotted-quad representation of an IPv4 network address as a string, returns an integer that represents the numeric value of the address in network byte order (big endian). INET_ATON() returns NULL if it does not understand its argument. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html :mysql> SELECT INET_ATON('10.0.5.9'); -> 167773449 Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlP UNCOMPRESS vSyntax: UNCOMPRESS(string_to_uncompress) Uncompresses a string compressed by the COMPRESS() function. If the argument is not a compressed value, the result is NULL. This function requires MySQL to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html mysql> SELECT UNCOMPRESS(COMPRESS('any string')); -> 'any string' mysql> SELECT UNCOMPRESS('any string'); -> NULL @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlAUTO_INCREMENTThe AUTO_INCREMENT attribute can be used to generate a unique identity for new rows: URL: http://dev.mysql.com/doc/refman/5.5/en/example-auto-increment.html CREATE TABLE animals ( id MEDIUMINT NOT NULL AUTO_INCREMENT, name CHAR(30) NOT NULL, PRIMARY KEY (id) ); INSERT INTO animals (name) VALUES ('dog'),('cat'),('penguin'), ('lax'),('whale'),('ostrich'); SELECT * FROM animals; Bhttp://dev.mysql.com/doc/refman/5.5/en/example-auto-increment.html ISSIMPLE$IsSimple(g) Currently, this function is a placeholder and should not be used. If implemented, its behavior will be as described in the next paragraph. Returns 1 if the geometry value g has no anomalous geometric points, such as self-intersection or self-tangency. IsSimple() returns 0 if the argument is not simple, and -1 if it is NULL. The description of each instantiable geometric class given earlier in the chapter includes the specific conditions that cause an instance of that class to be classified as not simple. (See [HELP Geometry hierarchy].) URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions- BINARY`Syntax: - Subtraction: URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html !mysql> SELECT 3-5; -> -2 @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.htmlaGEOMCOLLFROMTEXTGeomCollFromText(wkt[,srid]), GeometryCollectionFromText(wkt[,srid]) Constructs a GEOMETRYCOLLECTION value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functionsWKT DEFINITION~The Well-Known Text (WKT) representation of Geometry is designed to exchange geometry data in ASCII form. For a Backus-Naur grammar that specifies the formal production rules for writing WKT values, see the OpenGIS specification document referenced in http://dev.mysql.com/doc/refman/5.5/en/spatial-extensions.html. URL: http://dev.mysql.com/doc/refman/5.5/en/gis-wkt-format.html :http://dev.mysql.com/doc/refman/5.5/en/gis-wkt-format.html CURRENT_TIMESyntax: CURRENT_TIME, CURRENT_TIME() CURRENT_TIME and CURRENT_TIME() are synonyms for CURTIME(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html`REVOKE Syntax: REVOKE priv_type [(column_list)] [, priv_type [(column_list)]] ... ON [object_type] priv_level FROM user [, user] ... REVOKE ALL PRIVILEGES, GRANT OPTION FROM user [, user] ... REVOKE PROXY ON user FROM user [, user] ... The REVOKE statement enables system administrators to revoke privileges from MySQL accounts. Each account name uses the format described in http://dev.mysql.com/doc/refman/5.5/en/account-names.html. For example: REVOKE INSERT ON *.* FROM 'jeffrey'@'localhost'; If you specify only the user name part of the account name, a host name part of '%' is used. For details on the levels at which privileges exist, the permissible priv_type and priv_level values, and the syntax for specifying users and passwords, see [HELP GRANT] To use the first REVOKE syntax, you must have the GRANT OPTION privilege, and you must have the privileges that you are revoking. To revoke all privileges, use the second syntax, which drops all global, database, table, column, and routine privileges for the named user or users: REVOKE ALL PRIVILEGES, GRANT OPTION FROM user [, user] ... To use this REVOKE syntax, you must have the global CREATE USER privilege or the UPDATE privilege for the mysql database. URL: http://dev.mysql.com/doc/refman/5.5/en/revoke.html 2http://dev.mysql.com/doc/refman/5.5/en/revoke.htmlLAST_INSERT_IDSyntax: LAST_INSERT_ID(), LAST_INSERT_ID(expr) LAST_INSERT_ID() (with no argument) returns a BIGINT (64-bit) value representing the first automatically generated value successfully inserted for an AUTO_INCREMENT column as a result of the most recently executed INSERT statement. The value of LAST_INSERT_ID() remains unchanged if no rows are successfully inserted. For example, after inserting a row that generates an AUTO_INCREMENT value, you can get the value like this: mysql> SELECT LAST_INSERT_ID(); -> 195 The currently executing statement does not affect the value of LAST_INSERT_ID(). Suppose that you generate an AUTO_INCREMENT value with one statement, and then refer to LAST_INSERT_ID() in a multiple-row INSERT statement that inserts rows into a table with its own AUTO_INCREMENT column. The value of LAST_INSERT_ID() will remain stable in the second statement; its value for the second and later rows is not affected by the earlier row insertions. (However, if you mix references to LAST_INSERT_ID() and LAST_INSERT_ID(expr), the effect is undefined.) If the previous statement returned an error, the value of LAST_INSERT_ID() is undefined. For transactional tables, if the statement is rolled back due to an error, the value of LAST_INSERT_ID() is left undefined. For manual ROLLBACK, the value of LAST_INSERT_ID() is not restored to that before the transaction; it remains as it was at the point of the ROLLBACK. Within the body of a stored routine (procedure or function) or a trigger, the value of LAST_INSERT_ID() changes the same way as for statements executed outside the body of these kinds of objects. The effect of a stored routine or trigger upon the value of LAST_INSERT_ID() that is seen by following statements depends on the kind of routine: o If a stored procedure executes statements that change the value of LAST_INSERT_ID(), the changed value is seen by statements that follow the procedure call. o For stored functions and triggers that change the value, the value is restored when the function or trigger ends, so following statements will not see a changed value. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html@LAST_DAYSyntax: LAST_DAY(date) Takes a date or datetime value and returns the corresponding value for the last day of the month. Returns NULL if the argument is invalid. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT LAST_DAY('2003-02-05'); -> '2003-02-28' mysql> SELECT LAST_DAY('2004-02-05'); -> '2004-02-29' mysql> SELECT LAST_DAY('2004-01-01 01:01:01'); -> '2004-01-31' mysql> SELECT LAST_DAY('2003-03-32'); -> NULL Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html+ MEDIUMINTMEDIUMINT[(M)] [UNSIGNED] [ZEROFILL] A medium-sized integer. The signed range is -8388608 to 8388607. The unsigned range is 0 to 16777215. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html9FLOORSyntax: FLOOR(X) Returns the largest integer value not greater than X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Rmysql> SELECT FLOOR(1.23); -> 1 mysql> SELECT FLOOR(-1.23); -> -2 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlRTRIM%Syntax: RTRIM(str) Returns the string str with trailing space characters removed. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 6mysql> SELECT RTRIM('barbar '); -> 'barbar' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlEXPLAINSyntax: EXPLAIN [explain_type] SELECT select_options explain_type: EXTENDED | PARTITIONS Or: EXPLAIN tbl_name The EXPLAIN statement can be used either as a way to obtain information about how MySQL executes a statement, or as a synonym for DESCRIBE: o When you precede a SELECT statement with the keyword EXPLAIN, MySQL displays information from the optimizer about the query execution plan. That is, MySQL explains how it would process the statement, including information about how tables are joined and in which order. EXPLAIN EXTENDED can be used to obtain additional information. For information about using EXPLAIN and EXPLAIN EXTENDED to obtain query execution plan information, see http://dev.mysql.com/doc/refman/5.5/en/using-explain.html. o EXPLAIN PARTITIONS is useful only when examining queries involving partitioned tables. For details, see http://dev.mysql.com/doc/refman/5.5/en/partitioning-info.html. o EXPLAIN tbl_name is synonymous with DESCRIBE tbl_name or SHOW COLUMNS FROM tbl_name. For information about DESCRIBE and SHOW COLUMNS, see [HELP DESCRIBE], and [HELP SHOW COLUMNS]. URL: http://dev.mysql.com/doc/refman/5.5/en/explain.html 3http://dev.mysql.com/doc/refman/5.5/en/explain.htmlKDEGREESSyntax: DEGREES(X) Returns the argument X, converted from radians to degrees. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html [mysql> SELECT DEGREES(PI()); -> 180 mysql> SELECT DEGREES(PI() / 2); -> 90 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlVARCHARi[NATIONAL] VARCHAR(M) [CHARACTER SET charset_name] [COLLATE collation_name] A variable-length string. M represents the maximum column length in characters. The range of M is 0 to 65,535. The effective maximum length of a VARCHAR is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used. For example, utf8 characters can require up to three bytes per character, so a VARCHAR column that uses the utf8 character set can be declared to be a maximum of 21,844 characters. See http://dev.mysql.com/doc/refman/5.5/en/column-count-limit.html. MySQL stores VARCHAR values as a 1-byte or 2-byte length prefix plus data. The length prefix indicates the number of bytes in the value. A VARCHAR column uses one length byte if values require no more than 255 bytes, two length bytes if values may require more than 255 bytes. *Note*: MySQL 5.5 follows the standard SQL specification, and does not remove trailing spaces from VARCHAR values. VARCHAR is shorthand for CHARACTER VARYING. NATIONAL VARCHAR is the standard SQL way to define that a VARCHAR column should use some predefined character set. MySQL 4.1 and up uses utf8 as this predefined character set. http://dev.mysql.com/doc/refman/5.5/en/charset-national.html. NVARCHAR is shorthand for NATIONAL VARCHAR. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlUNHEX%cSyntax: UNHEX(str) For a string argument str, UNHEX(str) performs the inverse operation of HEX(str). That is, it interprets each pair of characters in the argument as a hexadecimal number and converts it to the character represented by the number. The return value is a binary string. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT UNHEX('4D7953514C'); -> 'MySQL' mysql> SELECT 0x4D7953514C; -> 'MySQL' mysql> SELECT UNHEX(HEX('string')); -> 'string' mysql> SELECT HEX(UNHEX('1267')); -> '1267' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html- UNARYSyntax: - Unary minus. This operator changes the sign of the operand. URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html !mysql> SELECT - 2; -> -2 @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.htmlwSTD*Syntax: STD(expr) Returns the population standard deviation of expr. This is an extension to standard SQL. The standard SQL function STDDEV_POP() can be used instead. This function returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html COSSyntax: COS(X) Returns the cosine of X, where X is given in radians. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html 'mysql> SELECT COS(PI()); -> -1 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html@ DATE FUNCTIONSyntax: DATE(expr) Extracts the date part of the date or datetime expression expr. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Cmysql> SELECT DATE('2003-12-31 01:02:03'); -> '2003-12-31' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html DROP TRIGGER'WSyntax: DROP TRIGGER [IF EXISTS] [schema_name.]trigger_name This statement drops a trigger. The schema (database) name is optional. If the schema is omitted, the trigger is dropped from the default schema. DROP TRIGGER requires the TRIGGER privilege for the table associated with the trigger. Use IF EXISTS to prevent an error from occurring for a trigger that does not exist. A NOTE is generated for a nonexistent trigger when using IF EXISTS. See [HELP SHOW WARNINGS]. Triggers for a table are also dropped if you drop the table. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-trigger.html 8http://dev.mysql.com/doc/refman/5.5/en/drop-trigger.html RESET MASTER8Syntax: RESET MASTER Deletes all binary log files listed in the index file, resets the binary log index file to be empty, and creates a new binary log file. This statement is intended to be used only when the master is started for the first time. URL: http://dev.mysql.com/doc/refman/5.5/en/reset-master.html 8http://dev.mysql.com/doc/refman/5.5/en/reset-master.htmlS TANSyntax: TAN(X) Returns the tangent of X, where X is given in radians. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html omysql> SELECT TAN(PI()); -> -1.2246063538224e-16 mysql> SELECT TAN(PI()+1); -> 1.5574077246549 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html PISyntax: PI() Returns the value of π (pi). The default number of decimal places displayed is seven, but MySQL uses the full double-precision value internally. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html qmysql> SELECT PI(); -> 3.141593 mysql> SELECT PI()+0.000000000000000000; -> 3.141592653589793116 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html  WEEKOFYEARSyntax: WEEKOFYEAR(date) Returns the calendar week of the date as a number in the range from 1 to 53. WEEKOFYEAR() is a compatibility function that is equivalent to WEEK(date,3). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 5mysql> SELECT WEEKOFYEAR('2008-02-20'); -> 8 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html /]Syntax: / Division: URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html #mysql> SELECT 3/5; -> 0.60 @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html PURGE BINARY LOGS+Syntax: PURGE { BINARY | MASTER } LOGS { TO 'log_name' | BEFORE datetime_expr } The binary log is a set of files that contain information about data modifications made by the MySQL server. The log consists of a set of binary log files, plus an index file (see http://dev.mysql.com/doc/refman/5.5/en/binary-log.html). The PURGE BINARY LOGS statement deletes all the binary log files listed in the log index file prior to the specified log file name or date. BINARY and MASTER are synonyms. Deleted log files also are removed from the list recorded in the index file, so that the given log file becomes the first in the list. This statement has no effect if the server was not started with the --log-bin option to enable binary logging. URL: http://dev.mysql.com/doc/refman/5.5/en/purge-binary-logs.html VPURGE BINARY LOGS TO 'mysql-bin.010'; PURGE BINARY LOGS BEFORE '2008-04-02 22:46:26'; =http://dev.mysql.com/doc/refman/5.5/en/purge-binary-logs.html@ STDDEV_SAMPSyntax: STDDEV_SAMP(expr) Returns the sample standard deviation of expr (the square root of VAR_SAMP(). STDDEV_SAMP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlSCHEMASyntax: SCHEMA() This function is a synonym for DATABASE(). URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.htmlR MLINEFROMWKB MLineFromWKB(wkb[,srid]), MultiLineStringFromWKB(wkb[,srid]) Constructs a MULTILINESTRING value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions%LOG2~Syntax: LOG2(X) Returns the base-2 logarithm of X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Smysql> SELECT LOG2(65536); -> 16 mysql> SELECT LOG2(-100); -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html$SUBTIMESyntax: SUBTIME(expr1,expr2) SUBTIME() returns expr1 - expr2 expressed as a value in the same format as expr1. expr1 is a time or datetime expression, and expr2 is a time expression. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT SUBTIME('2007-12-31 23:59:59.999999','1 1:1:1.000002'); -> '2007-12-30 22:58:58.999997' mysql> SELECT SUBTIME('01:00:00.999999', '02:00:00.999998'); -> '-00:59:59.999999' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmloUNCOMPRESSED_LENGTH Syntax: UNCOMPRESSED_LENGTH(compressed_string) Returns the length that the compressed string had before being compressed. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html Kmysql> SELECT UNCOMPRESSED_LENGTH(COMPRESS(REPEAT('a',30))); -> 30 @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlh DROP TABLE'Syntax: DROP [TEMPORARY] TABLE [IF EXISTS] tbl_name [, tbl_name] ... [RESTRICT | CASCADE] DROP TABLE removes one or more tables. You must have the DROP privilege for each table. All table data and the table definition are removed, so be careful with this statement! If any of the tables named in the argument list do not exist, MySQL returns an error indicating by name which nonexisting tables it was unable to drop, but it also drops all of the tables in the list that do exist. *Important*: When a table is dropped, user privileges on the table are not automatically dropped. See [HELP GRANT]. Note that for a partitioned table, DROP TABLE permanently removes the table definition, all of its partitions, and all of the data which was stored in those partitions. It also removes the partitioning definition (.par) file associated with the dropped table. Use IF EXISTS to prevent an error from occurring for tables that do not exist. A NOTE is generated for each nonexistent table when using IF EXISTS. See [HELP SHOW WARNINGS]. RESTRICT and CASCADE are permitted to make porting easier. In MySQL 5.5, they do nothing. *Note*: DROP TABLE automatically commits the current active transaction, unless you use the TEMPORARY keyword. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-table.html 6http://dev.mysql.com/doc/refman/5.5/en/drop-table.html.POWSyntax: POW(X,Y) Returns the value of X raised to the power of Y. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Nmysql> SELECT POW(2,2); -> 4 mysql> SELECT POW(2,-2); -> 0.25 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlSHOW CREATE TABLESyntax: SHOW CREATE TABLE tbl_name Shows the CREATE TABLE statement that creates the given table. To use this statement, you must have some privilege for the table. This statement also works with views. SHOW CREATE TABLE quotes table and column names according to the value of the sql_quote_show_create option. See http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-table.html mysql> SHOW CREATE TABLE t\G *************************** 1. row *************************** Table: t Create Table: CREATE TABLE t ( id INT(11) default NULL auto_increment, s char(60) default NULL, PRIMARY KEY (id) ) ENGINE=MyISAM =http://dev.mysql.com/doc/refman/5.5/en/show-create-table.htmlDUALYou are permitted to specify DUAL as a dummy table name in situations where no tables are referenced: mysql> SELECT 1 + 1 FROM DUAL; -> 2 DUAL is purely for the convenience of people who require that all SELECT statements should have FROM and possibly other clauses. MySQL may ignore the clauses. MySQL does not require FROM DUAL if no tables are referenced. URL: http://dev.mysql.com/doc/refman/5.5/en/select.html 2http://dev.mysql.com/doc/refman/5.5/en/select.htmlINSTR%Syntax: INSTR(str,substr) Returns the position of the first occurrence of substring substr in string str. This is the same as the two-argument form of LOCATE(), except that the order of the arguments is reversed. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html jmysql> SELECT INSTR('foobarbar', 'bar'); -> 4 mysql> SELECT INSTR('xbar', 'foobar'); -> 0 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlNOW<Syntax: NOW() Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html pmysql> SELECT NOW(); -> '2007-12-15 23:50:26' mysql> SELECT NOW() + 0; -> 20071215235026.000000 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmls SHOW ENGINES#Syntax: SHOW [STORAGE] ENGINES SHOW ENGINES displays status information about the server's storage engines. This is particularly useful for checking whether a storage engine is supported, or to see what the default engine is. URL: http://dev.mysql.com/doc/refman/5.5/en/show-engines.html 8http://dev.mysql.com/doc/refman/5.5/en/show-engines.html>=kSyntax: >= Greater than or equal: URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html #mysql> SELECT 2 >= 2; -> 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlEXPSyntax: EXP(X) Returns the value of e (the base of natural logarithms) raised to the power of X. The inverse of this function is LOG() (using a single argument only) or LN(). URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT EXP(2); -> 7.3890560989307 mysql> SELECT EXP(-2); -> 0.13533528323661 mysql> SELECT EXP(0); -> 1 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlLONGBLOBLONGBLOB A BLOB column with a maximum length of 4,294,967,295 or 4GB (232 - 1) bytes. The effective maximum length of LONGBLOB columns depends on the configured maximum packet size in the client/server protocol and available memory. Each LONGBLOB value is stored using a 4-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmltPOINTN PointN(ls,N) Returns the N-th Point in the Linestring value ls. Points are numbered beginning with 1. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functions 'mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(PointN(GeomFromText(@ls),2)); +-------------------------------------+ | AsText(PointN(GeomFromText(@ls),2)) | +-------------------------------------+ | POINT(2 2) | +-------------------------------------+ ehttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functionsYEAR DATA TYPEYEAR[(2|4)] A year in two-digit or four-digit format. The default is four-digit format. YEAR(2) or YEAR(4) differ in display format, but have the same range of values. In four-digit format, values display as 1901 to 2155, and 0000. In two-digit format, values display as 70 to 69, representing years from 1970 to 2069. MySQL displays YEAR values in YYYY or YYformat, but permits assignment of values to YEAR columns using either strings or numbers. *Note*: The YEAR(2) data type has certain issues that you should consider before choosing to use it. As of MySQL 5.5.27, YEAR(2) is deprecated. For more information, see http://dev.mysql.com/doc/refman/5.5/en/migrating-to-year4.html. For additional information about YEAR display format and inerpretation of input values, see http://dev.mysql.com/doc/refman/5.5/en/year.html. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html{ SUM.Syntax: SUM([DISTINCT] expr) Returns the sum of expr. If the return set has no rows, SUM() returns NULL. The DISTINCT keyword can be used to sum only the distinct values of expr. SUM() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlg!OCT%Syntax: OCT(N) Returns a string representation of the octal value of N, where N is a longlong (BIGINT) number. This is equivalent to CONV(N,10,8). Returns NULL if N is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 'mysql> SELECT OCT(12); -> '14' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html*"SYSDATESyntax: SYSDATE() Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. SYSDATE() returns the time at which it executes. This differs from the behavior for NOW(), which returns a constant time that indicates the time at which the statement began to execute. (Within a stored function or trigger, NOW() returns the time at which the function or triggering statement began to execute.) mysql> SELECT NOW(), SLEEP(2), NOW(); +---------------------+----------+---------------------+ | NOW() | SLEEP(2) | NOW() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:36 | 0 | 2006-04-12 13:47:36 | +---------------------+----------+---------------------+ mysql> SELECT SYSDATE(), SLEEP(2), SYSDATE(); +---------------------+----------+---------------------+ | SYSDATE() | SLEEP(2) | SYSDATE() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:44 | 0 | 2006-04-12 13:47:46 | +---------------------+----------+---------------------+ In addition, the SET TIMESTAMP statement affects the value returned by NOW() but not by SYSDATE(). This means that timestamp settings in the binary log have no effect on invocations of SYSDATE(). Because SYSDATE() can return different values even within the same statement, and is not affected by SET TIMESTAMP, it is nondeterministic and therefore unsafe for replication if statement-based binary logging is used. If that is a problem, you can use row-based logging. Alternatively, you can use the --sysdate-is-now option to cause SYSDATE() to be an alias for NOW(). This works if the option is used on both the master and the slave. The nondeterministic nature of SYSDATE() also means that indexes cannot be used for evaluating expressions that refer to it. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#UNINSTALL PLUGIN;Syntax: UNINSTALL PLUGIN plugin_name This statement removes an installed server plugin. It requires the DELETE privilege for the mysql.plugin table. plugin_name must be the name of some plugin that is listed in the mysql.plugin table. The server executes the plugin's deinitialization function and removes the row for the plugin from the mysql.plugin table, so that subsequent server restarts will not load and initialize the plugin. UNINSTALL PLUGIN does not remove the plugin's shared library file. URL: http://dev.mysql.com/doc/refman/5.5/en/uninstall-plugin.html <http://dev.mysql.com/doc/refman/5.5/en/uninstall-plugin.htmlo$ASBINARY AsBinary(g), AsWKB(g) Converts a value in internal geometry format to its WKB representation and returns the binary result. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-to-convert-geometries-between-formats.html SELECT AsBinary(g) FROM geom; [http://dev.mysql.com/doc/refman/5.5/en/functions-to-convert-geometries-between-formats.html%REPEAT FUNCTION%Syntax: REPEAT(str,count) Returns a string consisting of the string str repeated count times. If count is less than 1, returns an empty string. Returns NULL if str or count are NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html ?mysql> SELECT REPEAT('MySQL', 3); -> 'MySQLMySQLMySQL' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html& SHOW TABLESISyntax: SHOW [FULL] TABLES [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW TABLES lists the non-TEMPORARY tables in a given database. You can also get this list using the mysqlshow db_name command. The LIKE clause, if present, indicates which table names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. This statement also lists any views in the database. The FULL modifier is supported such that SHOW FULL TABLES displays a second output column. Values for the second column are BASE TABLE for a table and VIEW for a view. If you have no privileges for a base table or view, it does not show up in the output from SHOW TABLES or mysqlshow db_name. URL: http://dev.mysql.com/doc/refman/5.5/en/show-tables.html 7http://dev.mysql.com/doc/refman/5.5/en/show-tables.html'MAKEDATESyntax: MAKEDATE(year,dayofyear) Returns a date, given year and day-of-year values. dayofyear must be greater than 0 or the result is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT MAKEDATE(2011,31), MAKEDATE(2011,32); -> '2011-01-31', '2011-02-01' mysql> SELECT MAKEDATE(2011,365), MAKEDATE(2014,365); -> '2011-12-31', '2014-12-31' mysql> SELECT MAKEDATE(2011,0); -> NULL Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html(BINARY OPERATOR%Syntax: BINARY The BINARY operator casts the string following it to a binary string. This is an easy way to force a column comparison to be done byte by byte rather than character by character. This causes the comparison to be case sensitive even if the column is not defined as BINARY or BLOB. BINARY also causes trailing spaces to be significant. URL: http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html mysql> SELECT 'a' = 'A'; -> 1 mysql> SELECT BINARY 'a' = 'A'; -> 0 mysql> SELECT 'a' = 'a '; -> 1 mysql> SELECT BINARY 'a' = 'a '; -> 0 :http://dev.mysql.com/doc/refman/5.5/en/cast-functions.htmla) MBROVERLAPSMBROverlaps(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 overlap. The term spatially overlaps is used if two geometries intersect and their intersection results in a geometry of the same dimension but not equal to either of the given geometries. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr*SOUNDEX%Syntax: SOUNDEX(str) Returns a soundex string from str. Two strings that sound almost the same should have identical soundex strings. A standard soundex string is four characters long, but the SOUNDEX() function returns an arbitrarily long string. You can use SUBSTRING() on the result to get a standard soundex string. All nonalphabetic characters in str are ignored. All international alphabetic characters outside the A-Z range are treated as vowels. *Important*: When using SOUNDEX(), you should be aware of the following limitations: o This function, as currently implemented, is intended to work well with strings that are in the English language only. Strings in other languages may not produce reliable results. o This function is not guaranteed to provide consistent results with strings that use multi-byte character sets, including utf-8. We hope to remove these limitations in a future release. See Bug #22638 for more information. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html nmysql> SELECT SOUNDEX('Hello'); -> 'H400' mysql> SELECT SOUNDEX('Quadratically'); -> 'Q36324' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmld+ MBRTOUCHESMBRTouches(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 touch. Two geometries spatially touch if the interiors of the geometries do not intersect, but the boundary of one of the geometries intersects either the boundary or the interior of the other. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbrv, DROP EVENT'*Syntax: DROP EVENT [IF EXISTS] event_name This statement drops the event named event_name. The event immediately ceases being active, and is deleted completely from the server. If the event does not exist, the error ERROR 1517 (HY000): Unknown event 'event_name' results. You can override this and cause the statement to generate a warning for nonexistent events instead using IF EXISTS. This statement requires the EVENT privilege for the schema to which the event to be dropped belongs. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-event.html 6http://dev.mysql.com/doc/refman/5.5/en/drop-event.html- INSERT SELECTSyntax: INSERT [LOW_PRIORITY | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] SELECT ... [ ON DUPLICATE KEY UPDATE col_name=expr, ... ] With INSERT ... SELECT, you can quickly insert many rows into a table from one or many tables. For example: INSERT INTO tbl_temp2 (fld_id) SELECT tbl_temp1.fld_order_id FROM tbl_temp1 WHERE tbl_temp1.fld_order_id > 100; URL: http://dev.mysql.com/doc/refman/5.5/en/insert-select.html 9http://dev.mysql.com/doc/refman/5.5/en/insert-select.html#.CREATE PROCEDURE'#Syntax: CREATE [DEFINER = { user | CURRENT_USER }] PROCEDURE sp_name ([proc_parameter[,...]]) [characteristic ...] routine_body CREATE [DEFINER = { user | CURRENT_USER }] FUNCTION sp_name ([func_parameter[,...]]) RETURNS type [characteristic ...] routine_body proc_parameter: [ IN | OUT | INOUT ] param_name type func_parameter: param_name type type: Any valid MySQL data type characteristic: COMMENT 'string' | LANGUAGE SQL | [NOT] DETERMINISTIC | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } routine_body: Valid SQL routine statement These statements create stored routines. By default, a routine is associated with the default database. To associate the routine explicitly with a given database, specify the name as db_name.sp_name when you create it. The CREATE FUNCTION statement is also used in MySQL to support UDFs (user-defined functions). See http://dev.mysql.com/doc/refman/5.5/en/adding-functions.html. A UDF can be regarded as an external stored function. Stored functions share their namespace with UDFs. See http://dev.mysql.com/doc/refman/5.5/en/function-resolution.html, for the rules describing how the server interprets references to different kinds of functions. To invoke a stored procedure, use the CALL statement (see [HELP CALL]). To invoke a stored function, refer to it in an expression. The function returns a value during expression evaluation. CREATE PROCEDURE and CREATE FUNCTION require the CREATE ROUTINE privilege. They might also require the SUPER privilege, depending on the DEFINER value, as described later in this section. If binary logging is enabled, CREATE FUNCTION might require the SUPER privilege, as described in http://dev.mysql.com/doc/refman/5.5/en/stored-programs-logging.html. By default, MySQL automatically grants the ALTER ROUTINE and EXECUTE privileges to the routine creator. This behavior can be changed by disabling the automatic_sp_privileges system variable. See http://dev.mysql.com/doc/refman/5.5/en/stored-routines-privileges.html. The DEFINER and SQL SECURITY clauses specify the security context to be used when checking access privileges at routine execution time, as described later in this section. If the routine name is the same as the name of a built-in SQL function, a syntax error occurs unless you use a space between the name and the following parenthesis when defining the routine or invoking it later. For this reason, avoid using the names of existing SQL functions for your own stored routines. The IGNORE_SPACE SQL mode applies to built-in functions, not to stored routines. It is always permissible to have spaces after a stored routine name, regardless of whether IGNORE_SPACE is enabled. The parameter list enclosed within parentheses must always be present. If there are no parameters, an empty parameter list of () should be used. Parameter names are not case sensitive. Each parameter is an IN parameter by default. To specify otherwise for a parameter, use the keyword OUT or INOUT before the parameter name. *Note*: Specifying a parameter as IN, OUT, or INOUT is valid only for a PROCEDURE. For a FUNCTION, parameters are always regarded as IN parameters. An IN parameter passes a value into a procedure. The procedure might modify the value, but the modification is not visible to the caller when the procedure returns. An OUT parameter passes a value from the procedure back to the caller. Its initial value is NULL within the procedure, and its value is visible to the caller when the procedure returns. An INOUT parameter is initialized by the caller, can be modified by the procedure, and any change made by the procedure is visible to the caller when the procedure returns. For each OUT or INOUT parameter, pass a user-defined variable in the CALL statement that invokes the procedure so that you can obtain its value when the procedure returns. If you are calling the procedure from within another stored procedure or function, you can also pass a routine parameter or local routine variable as an IN or INOUT parameter. The following example shows a simple stored procedure that uses an OUT parameter: mysql> delimiter // mysql> CREATE PROCEDURE simpleproc (OUT param1 INT) -> BEGIN -> SELECT COUNT(*) INTO param1 FROM t; -> END// Query OK, 0 rows affected (0.00 sec) mysql> delimiter ; mysql> CALL simpleproc(@a); Query OK, 0 rows affected (0.00 sec) mysql> SELECT @a; +------+ | @a | +------+ | 3 | +------+ 1 row in set (0.00 sec) The example uses the mysql client delimiter command to change the statement delimiter from ; to // while the procedure is being defined. This enables the ; delimiter used in the procedure body to be passed through to the server rather than being interpreted by mysql itself. See http://dev.mysql.com/doc/refman/5.5/en/stored-programs-defining.html. The RETURNS clause may be specified only for a FUNCTION, for which it is mandatory. It indicates the return type of the function, and the function body must contain a RETURN value statement. If the RETURN statement returns a value of a different type, the value is coerced to the proper type. For example, if a function specifies an ENUM or SET value in the RETURNS clause, but the RETURN statement returns an integer, the value returned from the function is the string for the corresponding ENUM member of set of SET members. The following example function takes a parameter, performs an operation using an SQL function, and returns the result. In this case, it is unnecessary to use delimiter because the function definition contains no internal ; statement delimiters: mysql> CREATE FUNCTION hello (s CHAR(20)) mysql> RETURNS CHAR(50) DETERMINISTIC -> RETURN CONCAT('Hello, ',s,'!'); Query OK, 0 rows affected (0.00 sec) mysql> SELECT hello('world'); +----------------+ | hello('world') | +----------------+ | Hello, world! | +----------------+ 1 row in set (0.00 sec) Parameter types and function return types can be declared to use any valid data type, except that the COLLATE attribute cannot be used prior to MySQL 5.5.3. As of 5.5.3, COLLATE can be used if preceded by the CHARACTER SET attribute. The routine_body consists of a valid SQL routine statement. This can be a simple statement such as SELECT or INSERT, or a compound statement written using BEGIN and END. Compound statements can contain declarations, loops, and other control structure statements. The syntax for these statements is described in http://dev.mysql.com/doc/refman/5.5/en/sql-syntax-compound-statements.h tml. MySQL permits routines to contain DDL statements, such as CREATE and DROP. MySQL also permits stored procedures (but not stored functions) to contain SQL transaction statements such as COMMIT. Stored functions may not contain statements that perform explicit or implicit commit or rollback. Support for these statements is not required by the SQL standard, which states that each DBMS vendor may decide whether to permit them. Statements that return a result set can be used within a stored procedure but not within a stored function. This prohibition includes SELECT statements that do not have an INTO var_list clause and other statements such as SHOW, EXPLAIN, and CHECK TABLE. For statements that can be determined at function definition time to return a result set, a Not allowed to return a result set from a function error occurs (ER_SP_NO_RETSET). For statements that can be determined only at runtime to return a result set, a PROCEDURE %s can't return a result set in the given context error occurs (ER_SP_BADSELECT). USE statements within stored routines are not permitted. When a routine is invoked, an implicit USE db_name is performed (and undone when the routine terminates). The causes the routine to have the given default database while it executes. References to objects in databases other than the routine default database should be qualified with the appropriate database name. For additional information about statements that are not permitted in stored routines, see http://dev.mysql.com/doc/refman/5.5/en/stored-program-restrictions.html . For information about invoking stored procedures from within programs written in a language that has a MySQL interface, see [HELP CALL]. MySQL stores the sql_mode system variable setting that is in effect at the time a routine is created, and always executes the routine with this setting in force, regardless of the server SQL mode in effect when the routine is invoked. The switch from the SQL mode of the invoker to that of the routine occurs after evaluation of arguments and assignment of the resulting values to routine parameters. If you define a routine in strict SQL mode but invoke it in nonstrict mode, assignment of arguments to routine parameters does not take place in strict mode. If you require that expressions passed to a routine be assigned in strict SQL mode, you should invoke the routine with strict mode in effect. URL: http://dev.mysql.com/doc/refman/5.5/en/create-procedure.html <http://dev.mysql.com/doc/refman/5.5/en/create-procedure.htmlW/ VARBINARYVARBINARY(M) The VARBINARY type is similar to the VARCHAR type, but stores binary byte strings rather than nonbinary character strings. M represents the maximum column length in bytes. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html0 LOAD INDEXSyntax: LOAD INDEX INTO CACHE tbl_index_list [, tbl_index_list] ... tbl_index_list: tbl_name [PARTITION (partition_list | ALL)] [[INDEX|KEY] (index_name[, index_name] ...)] [IGNORE LEAVES] partition_list: partition_name[, partition_name][, ...] The LOAD INDEX INTO CACHE statement preloads a table index into the key cache to which it has been assigned by an explicit CACHE INDEX statement, or into the default key cache otherwise. LOAD INDEX INTO CACHE is used only for MyISAM tables. In MySQL 5.5, it is also supported for partitioned MyISAM tables; in addition, indexes on partitioned tables can be preloaded for one, several, or all partitions. The IGNORE LEAVES modifier causes only blocks for the nonleaf nodes of the index to be preloaded. IGNORE LEAVES is also supported for partitioned MyISAM tables. URL: http://dev.mysql.com/doc/refman/5.5/en/load-index.html 6http://dev.mysql.com/doc/refman/5.5/en/load-index.html1UNIONVSyntax: SELECT ... UNION [ALL | DISTINCT] SELECT ... [UNION [ALL | DISTINCT] SELECT ...] UNION is used to combine the result from multiple SELECT statements into a single result set. The column names from the first SELECT statement are used as the column names for the results returned. Selected columns listed in corresponding positions of each SELECT statement should have the same data type. (For example, the first column selected by the first statement should have the same type as the first column selected by the other statements.) URL: http://dev.mysql.com/doc/refman/5.5/en/union.html 1http://dev.mysql.com/doc/refman/5.5/en/union.htmlm2TO_DAYSSyntax: TO_DAYS(date) Given a date date, returns a day number (the number of days since year 0). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html hmysql> SELECT TO_DAYS(950501); -> 728779 mysql> SELECT TO_DAYS('2007-10-07'); -> 733321 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html3 NOT REGEXP%Syntax: expr NOT REGEXP pat, expr NOT RLIKE pat This is the same as NOT (expr REGEXP pat). URL: http://dev.mysql.com/doc/refman/5.5/en/regexp.html 2http://dev.mysql.com/doc/refman/5.5/en/regexp.htmlJ4 SHOW INDEXSyntax: SHOW {INDEX | INDEXES | KEYS} {FROM | IN} tbl_name [{FROM | IN} db_name] [WHERE expr] SHOW INDEX returns table index information. The format resembles that of the SQLStatistics call in ODBC. This statement requires some privilege for any column in the table. You can use db_name.tbl_name as an alternative to the tbl_name FROM db_name syntax. These two statements are equivalent: SHOW INDEX FROM mytable FROM mydb; SHOW INDEX FROM mydb.mytable; The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. You can also list a table's indexes with the mysqlshow -k db_name tbl_name command. URL: http://dev.mysql.com/doc/refman/5.5/en/show-index.html 6http://dev.mysql.com/doc/refman/5.5/en/show-index.html|5SHOW CREATE DATABASEgSyntax: SHOW CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name Shows the CREATE DATABASE statement that creates the given database. If the SHOW statement includes an IF NOT EXISTS clause, the output too includes such a clause. SHOW CREATE SCHEMA is a synonym for SHOW CREATE DATABASE. URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-database.html mysql> SHOW CREATE DATABASE test\G *************************** 1. row *************************** Database: test Create Database: CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET latin1 */ mysql> SHOW CREATE SCHEMA test\G *************************** 1. row *************************** Database: test Create Database: CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET latin1 */ @http://dev.mysql.com/doc/refman/5.5/en/show-create-database.html6LEAVEESyntax: LEAVE label This statement is used to exit the flow control construct that has the given label. If the label is for the outermost stored program block, LEAVE exits the program. LEAVE can be used within BEGIN ... END or loop constructs (LOOP, REPEAT, WHILE). URL: http://dev.mysql.com/doc/refman/5.5/en/leave.html 1http://dev.mysql.com/doc/refman/5.5/en/leave.html7NOT INSyntax: expr NOT IN (value,...) This is the same as NOT (expr IN (value,...)). URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html8!Syntax: NOT, ! Logical NOT. Evaluates to 1 if the operand is 0, to 0 if the operand is nonzero, and NOT NULL returns NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html mysql> SELECT NOT 10; -> 0 mysql> SELECT NOT 0; -> 1 mysql> SELECT NOT NULL; -> NULL mysql> SELECT ! (1+1); -> 0 mysql> SELECT ! 1+1; -> 1 =http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html@9DECLARE HANDLER Syntax: DECLARE handler_action HANDLER FOR condition_value [, condition_value] ... statement handler_action: CONTINUE | EXIT | UNDO condition_value: mysql_error_code | SQLSTATE [VALUE] sqlstate_value | condition_name | SQLWARNING | NOT FOUND | SQLEXCEPTION The DECLARE ... HANDLER statement specifies a handler that deals with one or more conditions. If one of these conditions occurs, the specified statement executes. statement can be a simple statement such as SET var_name = value, or a compound statement written using BEGIN and END (see [HELP BEGIN END]). Handler declarations must appear after variable or condition declarations. The handler_action value indicates what action the handler takes after execution of the handler statement: o CONTINUE: Execution of the current program continues. o EXIT: Execution terminates for the BEGIN ... END compound statement in which the handler is declared. This is true even if the condition occurs in an inner block. o UNDO: Not supported. The condition_value for DECLARE ... HANDLER indicates the specific condition or class of conditions that activates the handler: o A MySQL error code (a number) or an SQLSTATE value (a 5-character string literal). You should not use MySQL error code 0 or SQLSTATE values that begin with '00', because those indicate success rather than an error condition. For a list of MySQL error codes and SQLSTATE values, see http://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html. o A condition name previously specified with DECLARE ... CONDITION. A condition name can be associated with a MySQL error code or SQLSTATE value. See [HELP DECLARE CONDITION]. o SQLWARNING is shorthand for the class of SQLSTATE values that begin with '01'. o NOT FOUND is shorthand for the class of SQLSTATE values that begin with '02'. This is relevant within the context of cursors and is used to control what happens when a cursor reaches the end of a data set. If no more rows are available, a No Data condition occurs with SQLSTATE value '02000'. To detect this condition, you can set up a handler for it (or for a NOT FOUND condition). For an example, see http://dev.mysql.com/doc/refman/5.5/en/cursors.html. This condition also occurs for SELECT ... INTO var_list statements that retrieve no rows. o SQLEXCEPTION is shorthand for the class of SQLSTATE values that do not begin with '00', '01', or '02'. If a condition occurs for which no handler has been declared, the action taken depends on the condition class: o For SQLEXCEPTION conditions, the stored program terminates at the statement that raised the condition, as if there were an EXIT handler. If the program was called by another stored program, the calling program handles the condition using the handler selection rules applied to its own handlers. o For SQLWARNING conditions, the program continues executing, as if there were a CONTINUE handler. o For NOT FOUND conditions, if the condition was raised normally, the action is CONTINUE. If it was raised by SIGNAL or RESIGNAL, the action is EXIT. URL: http://dev.mysql.com/doc/refman/5.5/en/declare-handler.html gmysql> CREATE TABLE test.t (s1 INT, PRIMARY KEY (s1)); Query OK, 0 rows affected (0.00 sec) mysql> delimiter // mysql> CREATE PROCEDURE handlerdemo () -> BEGIN -> DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' SET @x2 = 1; -> SET @x = 1; -> INSERT INTO test.t VALUES (1); -> SET @x = 2; -> INSERT INTO test.t VALUES (1); -> SET @x = 3; -> END; -> // Query OK, 0 rows affected (0.00 sec) mysql> CALL handlerdemo()// Query OK, 0 rows affected (0.00 sec) mysql> SELECT @x// +------+ | @x | +------+ | 3 | +------+ 1 row in set (0.00 sec) ;http://dev.mysql.com/doc/refman/5.5/en/declare-handler.htmlV:DOUBLEDOUBLE[(M,D)] [UNSIGNED] [ZEROFILL] A normal-size (double-precision) floating-point number. Permissible values are -1.7976931348623157E+308 to -2.2250738585072014E-308, 0, and 2.2250738585072014E-308 to 1.7976931348623157E+308. These are the theoretical limits, based on the IEEE standard. The actual range might be slightly smaller depending on your hardware or operating system. M is the total number of digits and D is the number of digits following the decimal point. If M and D are omitted, values are stored to the limits permitted by the hardware. A double-precision floating-point number is accurate to approximately 15 decimal places. UNSIGNED, if specified, disallows negative values. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmla;TIME TIME A time. The range is '-838:59:59' to '838:59:59'. MySQL displays TIME values in 'HH:MM:SS' format, but permits assignment of values to TIME columns using either strings or numbers. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html<&&Syntax: AND, && Logical AND. Evaluates to 1 if all operands are nonzero and not NULL, to 0 if one or more operands are 0, otherwise NULL is returned. URL: http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html mysql> SELECT 1 && 1; -> 1 mysql> SELECT 1 && 0; -> 0 mysql> SELECT 1 && NULL; -> NULL mysql> SELECT 0 && NULL; -> 0 mysql> SELECT NULL && 0; -> 0 =http://dev.mysql.com/doc/refman/5.5/en/logical-operators.html=X X(p) Returns the X-coordinate value for the Point object p as a double-precision number. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#point-property-functions mysql> SELECT X(POINT(56.7, 53.34)); +-----------------------+ | X(POINT(56.7, 53.34)) | +-----------------------+ | 56.7 | +-----------------------+ `http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#point-property-functions> SYSTEM_USERSyntax: SYSTEM_USER() SYSTEM_USER() is a synonym for USER(). URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html? FOUND_ROWSSyntax: FOUND_ROWS() A SELECT statement may include a LIMIT clause to restrict the number of rows the server returns to the client. In some cases, it is desirable to know how many rows the statement would have returned without the LIMIT, but without running the statement again. To obtain this row count, include a SQL_CALC_FOUND_ROWS option in the SELECT statement, and then invoke FOUND_ROWS() afterward: URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html nmysql> SELECT SQL_CALC_FOUND_ROWS * FROM tbl_name -> WHERE id > 100 LIMIT 10; mysql> SELECT FOUND_ROWS(); Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html~@CROSSESCrosses(g1,g2) Returns 1 if g1 spatially crosses g2. Returns NULL if g1 is a Polygon or a MultiPolygon, or if g2 is a Point or a MultiPoint. Otherwise, returns 0. The term spatially crosses denotes a spatial relation between two given geometries that has the following properties: o The two geometries intersect o Their intersection results in a geometry that has a dimension that is one less than the maximum dimension of the two given geometries o Their intersection is not equal to either of the two given geometries URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometriesFATRUNCATE TABLE'Syntax: TRUNCATE [TABLE] tbl_name TRUNCATE TABLE empties a table completely. It requires the DROP privilege. Logically, TRUNCATE TABLE is similar to a DELETE statement that deletes all rows, or a sequence of DROP TABLE and CREATE TABLE statements. To achieve high performance, it bypasses the DML method of deleting data. Thus, it cannot be rolled back, it does not cause ON DELETE triggers to fire, and it cannot be performed for InnoDB tables with parent-child foreign key relationships. Although TRUNCATE TABLE is similar to DELETE, it is classified as a DDL statement rather than a DML statement. It differs from DELETE in the following ways in MySQL 5.5: o Truncate operations drop and re-create the table, which is much faster than deleting rows one by one, particularly for large tables. o Truncate operations cause an implicit commit, and so cannot be rolled back. o Truncation operations cannot be performed if the session holds an active table lock. o TRUNCATE TABLE fails for an InnoDB table if there are any FOREIGN KEY constraints from other tables that reference the table. Foreign key constraints between columns of the same table are permitted. o Truncation operations do not return a meaningful value for the number of deleted rows. The usual result is "0 rows affected," which should be interpreted as "no information." o As long as the table format file tbl_name.frm is valid, the table can be re-created as an empty table with TRUNCATE TABLE, even if the data or index files have become corrupted. o Any AUTO_INCREMENT value is reset to its start value. This is true even for MyISAM and InnoDB, which normally do not reuse sequence values. o When used with partitioned tables, TRUNCATE TABLE preserves the partitioning; that is, the data and index files are dropped and re-created, while the partition definitions (.par) file is unaffected. o The TRUNCATE TABLE statement does not invoke ON DELETE triggers. URL: http://dev.mysql.com/doc/refman/5.5/en/truncate-table.html :http://dev.mysql.com/doc/refman/5.5/en/truncate-table.htmlBBIT_XORSyntax: BIT_XOR(expr) Returns the bitwise XOR of all bits in expr. The calculation is performed with 64-bit (BIGINT) precision. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlC CURRENT_DATESyntax: CURRENT_DATE, CURRENT_DATE() CURRENT_DATE and CURRENT_DATE() are synonyms for CURDATE(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlD START SLAVEfSyntax: START SLAVE [thread_types] START SLAVE [SQL_THREAD] UNTIL MASTER_LOG_FILE = 'log_name', MASTER_LOG_POS = log_pos START SLAVE [SQL_THREAD] UNTIL RELAY_LOG_FILE = 'log_name', RELAY_LOG_POS = log_pos thread_types: [thread_type [, thread_type] ... ] thread_type: IO_THREAD | SQL_THREAD START SLAVE with no thread_type options starts both of the slave threads. The I/O thread reads events from the master server and stores them in the relay log. The SQL thread reads events from the relay log and executes them. START SLAVE requires the SUPER privilege. If START SLAVE succeeds in starting the slave threads, it returns without any error. However, even in that case, it might be that the slave threads start and then later stop (for example, because they do not manage to connect to the master or read its binary log, or some other problem). START SLAVE does not warn you about this. You must check the slave's error log for error messages generated by the slave threads, or check that they are running satisfactorily with SHOW SLAVE STATUS. URL: http://dev.mysql.com/doc/refman/5.5/en/start-slave.html 7http://dev.mysql.com/doc/refman/5.5/en/start-slave.htmlbEAREAArea(poly) Returns as a double-precision number the area of the Polygon value poly, as measured in its spatial reference system. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functions mysql> SET @poly = 'Polygon((0 0,0 3,3 0,0 0),(1 1,1 2,2 1,1 1))'; mysql> SELECT Area(GeomFromText(@poly)); +---------------------------+ | Area(GeomFromText(@poly)) | +---------------------------+ | 4 | +---------------------------+ bhttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functions\FFLUSHSyntax: FLUSH [NO_WRITE_TO_BINLOG | LOCAL] flush_option [, flush_option] ... The FLUSH statement has several variant forms that clear or reload various internal caches, flush tables, or acquire locks. To execute FLUSH, you must have the RELOAD privilege. Specific flush options might require additional privileges, as described later. By default, the server writes FLUSH statements to the binary log so that they replicate to replication slaves. To suppress logging, use the optional NO_WRITE_TO_BINLOG keyword or its alias LOCAL. *Note*: FLUSH LOGS, FLUSH MASTER, FLUSH SLAVE, and FLUSH TABLES WITH READ LOCK (with or without a table list) are not written to the binary log in any case because they would cause problems if replicated to a slave. The FLUSH statement causes an implicit commit. See http://dev.mysql.com/doc/refman/5.5/en/implicit-commit.html. The RESET statement is similar to FLUSH. See [HELP RESET], for information about using the RESET statement with replication. URL: http://dev.mysql.com/doc/refman/5.5/en/flush.html 1http://dev.mysql.com/doc/refman/5.5/en/flush.htmlG BEGIN END6Syntax: [begin_label:] BEGIN [statement_list] END [end_label] BEGIN ... END syntax is used for writing compound statements, which can appear within stored programs (stored procedures and functions, triggers, and events). A compound statement can contain multiple statements, enclosed by the BEGIN and END keywords. statement_list represents a list of one or more statements, each terminated by a semicolon (;) statement delimiter. The statement_list itself is optional, so the empty compound statement (BEGIN END) is legal. BEGIN ... END blocks can be nested. Use of multiple statements requires that a client is able to send statement strings containing the ; statement delimiter. In the mysql command-line client, this is handled with the delimiter command. Changing the ; end-of-statement delimiter (for example, to //) permit ; to be used in a program body. For an example, see http://dev.mysql.com/doc/refman/5.5/en/stored-programs-defining.html. A BEGIN ... END block can be labeled. See [HELP labels]. URL: http://dev.mysql.com/doc/refman/5.5/en/begin-end.html 5http://dev.mysql.com/doc/refman/5.5/en/begin-end.htmlHSHOW PROCEDURE STATUSSyntax: SHOW PROCEDURE STATUS [LIKE 'pattern' | WHERE expr] This statement is a MySQL extension. It returns characteristics of a stored procedure, such as the database, name, type, creator, creation and modification dates, and character set information. A similar statement, SHOW FUNCTION STATUS, displays information about stored functions (see [HELP SHOW FUNCTION STATUS]). The LIKE clause, if present, indicates which procedure or function names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show-procedure-status.html mysql> SHOW PROCEDURE STATUS LIKE 'sp1'\G *************************** 1. row *************************** Db: test Name: sp1 Type: PROCEDURE Definer: testuser@localhost Modified: 2004-08-03 15:29:37 Created: 2004-08-03 15:29:37 Security_type: DEFINER Comment: character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci Ahttp://dev.mysql.com/doc/refman/5.5/en/show-procedure-status.htmlzIDESCRIBE2Syntax: {DESCRIBE | DESC} tbl_name [col_name | wild] DESCRIBE provides information about the columns in a table. It is a shortcut for SHOW COLUMNS FROM. These statements also display information for views. (See [HELP SHOW COLUMNS].) col_name can be a column name, or a string containing the SQL "%" and "_" wildcard characters to obtain output only for the columns with names matching the string. There is no need to enclose the string within quotation marks unless it contains spaces or other special characters. mysql> DESCRIBE City; +------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+----------+------+-----+---------+----------------+ | Id | int(11) | NO | PRI | NULL | auto_increment | | Name | char(35) | NO | | | | | Country | char(3) | NO | UNI | | | | District | char(20) | YES | MUL | | | | Population | int(11) | NO | | 0 | | +------------+----------+------+-----+---------+----------------+ 5 rows in set (0.00 sec) The description for SHOW COLUMNS provides more information about the output columns (see [HELP SHOW COLUMNS]). URL: http://dev.mysql.com/doc/refman/5.5/en/describe.html 4http://dev.mysql.com/doc/refman/5.5/en/describe.htmlJ SHOW WARNINGSSyntax: SHOW WARNINGS [LIMIT [offset,] row_count] SHOW COUNT(*) WARNINGS SHOW WARNINGS shows information about the conditions (errors, warnings, and notes) that resulted from the last statement in the current session that generated messages. It shows nothing if the last statement used a table and generated no messages. (That is, a statement that uses a table but generates no messages clears the message list.) Statements that do not use tables and do not generate messages have no effect on the message list. Warnings are generated for DML statements such as INSERT, UPDATE, and LOAD DATA INFILE as well as DDL statements such as CREATE TABLE and ALTER TABLE. SHOW WARNINGS is also used following EXPLAIN EXTENDED, to display the extra information generated by EXPLAIN when the EXTENDED keyword is used. See http://dev.mysql.com/doc/refman/5.5/en/explain-extended.html. The LIMIT clause has the same syntax as for the SELECT statement. See http://dev.mysql.com/doc/refman/5.5/en/select.html. A related statement, SHOW ERRORS, shows only the error conditions (it excludes warnings and notes). See [HELP SHOW ERRORS]. The SHOW COUNT(*) WARNINGS statement displays the total number of errors, warnings, and notes. You can also retrieve this number from the warning_count system variable: SHOW COUNT(*) WARNINGS; SELECT @@warning_count; URL: http://dev.mysql.com/doc/refman/5.5/en/show-warnings.html 9http://dev.mysql.com/doc/refman/5.5/en/show-warnings.htmlK DROP USER aSyntax: DROP USER user [, user] ... The DROP USER statement removes one or more MySQL accounts and their privileges. It removes privilege rows for the account from all grant tables. To use this statement, you must have the global CREATE USER privilege or the DELETE privilege for the mysql database. Each account name uses the format described in http://dev.mysql.com/doc/refman/5.5/en/account-names.html. For example: DROP USER 'jeffrey'@'localhost'; If you specify only the user name part of the account name, a host name part of '%' is used. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-user.html 5http://dev.mysql.com/doc/refman/5.5/en/drop-user.htmlL STDDEV_POP<Syntax: STDDEV_POP(expr) Returns the population standard deviation of expr (the square root of VAR_POP()). You can also use STD() or STDDEV(), which are equivalent but not standard SQL. STDDEV_POP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlvMSHOW CHARACTER SETSyntax: SHOW CHARACTER SET [LIKE 'pattern' | WHERE expr] The SHOW CHARACTER SET statement shows all available character sets. The LIKE clause, if present, indicates which character set names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. For example: mysql> SHOW CHARACTER SET LIKE 'latin%'; +---------+-----------------------------+-------------------+--------+ | Charset | Description | Default collation | Maxlen | +---------+-----------------------------+-------------------+--------+ | latin1 | cp1252 West European | latin1_swedish_ci | 1 | | latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 | | latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 | | latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 | +---------+-----------------------------+-------------------+--------+ URL: http://dev.mysql.com/doc/refman/5.5/en/show-character-set.html >http://dev.mysql.com/doc/refman/5.5/en/show-character-set.htmlN SUBSTRING%6Syntax: SUBSTRING(str,pos), SUBSTRING(str FROM pos), SUBSTRING(str,pos,len), SUBSTRING(str FROM pos FOR len) The forms without a len argument return a substring from string str starting at position pos. The forms with a len argument return a substring len characters long from string str, starting at position pos. The forms that use FROM are standard SQL syntax. It is also possible to use a negative value for pos. In this case, the beginning of the substring is pos characters from the end of the string, rather than the beginning. A negative value may be used for pos in any of the forms of this function. For all forms of SUBSTRING(), the position of the first character in the string from which the substring is to be extracted is reckoned as 1. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html zmysql> SELECT SUBSTRING('Quadratically',5); -> 'ratically' mysql> SELECT SUBSTRING('foobarbar' FROM 4); -> 'barbar' mysql> SELECT SUBSTRING('Quadratically',5,6); -> 'ratica' mysql> SELECT SUBSTRING('Sakila', -3); -> 'ila' mysql> SELECT SUBSTRING('Sakila', -5, 3); -> 'aki' mysql> SELECT SUBSTRING('Sakila' FROM -4 FOR 2); -> 'ki' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlOISEMPTY$+IsEmpty(g) Returns 1 if the geometry value g is the empty geometry, 0 if it is not empty, and -1 if the argument is NULL. If the geometry is empty, it represents the empty point set. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functionsWPSHOW FUNCTION STATUSSyntax: SHOW FUNCTION STATUS [LIKE 'pattern' | WHERE expr] This statement is similar to SHOW PROCEDURE STATUS but for stored functions. See [HELP SHOW PROCEDURE STATUS]. URL: http://dev.mysql.com/doc/refman/5.5/en/show-function-status.html @http://dev.mysql.com/doc/refman/5.5/en/show-function-status.htmlQLTRIM%Syntax: LTRIM(str) Returns the string str with leading space characters removed. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 5mysql> SELECT LTRIM(' barbar'); -> 'barbar' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlR INTERSECTSIntersects(g1,g2) Returns 1 or 0 to indicate whether g1 spatially intersects g2. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometriesSCALLSyntax: CALL sp_name([parameter[,...]]) CALL sp_name[()] The CALL statement invokes a stored procedure that was defined previously with CREATE PROCEDURE. Stored procedures that take no arguments can be invoked without parentheses. That is, CALL p() and CALL p are equivalent. CALL can pass back values to its caller using parameters that are declared as OUT or INOUT parameters. When the procedure returns, a client program can also obtain the number of rows affected for the final statement executed within the routine: At the SQL level, call the ROW_COUNT() function; from the C API, call the mysql_affected_rows() function. URL: http://dev.mysql.com/doc/refman/5.5/en/call.html 0http://dev.mysql.com/doc/refman/5.5/en/call.htmlT MBRDISJOINT'MBRDisjoint(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 are disjoint (do not intersect). URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbrxUVALUESSyntax: VALUES(col_name) In an INSERT ... ON DUPLICATE KEY UPDATE statement, you can use the VALUES(col_name) function in the UPDATE clause to refer to column values from the INSERT portion of the statement. In other words, VALUES(col_name) in the UPDATE clause refers to the value of col_name that would be inserted, had no duplicate-key conflict occurred. This function is especially useful in multiple-row inserts. The VALUES() function is meaningful only in the ON DUPLICATE KEY UPDATE clause of INSERT statements and returns NULL otherwise. See http://dev.mysql.com/doc/refman/5.5/en/insert-on-duplicate.html. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html nmysql> INSERT INTO table (a,b,c) VALUES (1,2,3),(4,5,6) -> ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b); Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlVSUBSTRING_INDEX%Syntax: SUBSTRING_INDEX(str,delim,count) Returns the substring from string str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is returned. SUBSTRING_INDEX() performs a case-sensitive match when searching for delim. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT SUBSTRING_INDEX('www.mysql.com', '.', 2); -> 'www.mysql' mysql> SELECT SUBSTRING_INDEX('www.mysql.com', '.', -2); -> 'mysql.com' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlWENCODE dSyntax: ENCODE(str,pass_str) Encrypt str using pass_str as the password. To decrypt the result, use DECODE(). The result is a binary string of the same length as str. The strength of the encryption is based on how good the random generator is. It should suffice for short strings. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlXLOOPSyntax: [begin_label:] LOOP statement_list END LOOP [end_label] LOOP implements a simple loop construct, enabling repeated execution of the statement list, which consists of one or more statements, each terminated by a semicolon (;) statement delimiter. The statements within the loop are repeated until the loop is terminated. Usually, this is accomplished with a LEAVE statement. Within a stored function, RETURN can also be used, which exits the function entirely. Neglecting to include a loop-termination statement results in an infinite loop. A LOOP statement can be labeled. For the rules regarding label use, see [HELP labels]. URL: http://dev.mysql.com/doc/refman/5.5/en/loop.html CREATE PROCEDURE doiterate(p1 INT) BEGIN label1: LOOP SET p1 = p1 + 1; IF p1 < 10 THEN ITERATE label1; END IF; LEAVE label1; END LOOP label1; SET @x = p1; END; 0http://dev.mysql.com/doc/refman/5.5/en/loop.htmlYTRUNCATE2Syntax: TRUNCATE(X,D) Returns the number X, truncated to D decimal places. If D is 0, the result has no decimal point or fractional part. D can be negative to cause D digits left of the decimal point of the value X to become zero. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html "mysql> SELECT TRUNCATE(1.223,1); -> 1.2 mysql> SELECT TRUNCATE(1.999,1); -> 1.9 mysql> SELECT TRUNCATE(1.999,0); -> 1 mysql> SELECT TRUNCATE(-1.999,1); -> -1.9 mysql> SELECT TRUNCATE(122,-2); -> 100 mysql> SELECT TRUNCATE(10.28*100,0); -> 1028 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlZ TIMESTAMPADDSyntax: TIMESTAMPADD(unit,interval,datetime_expr) Adds the integer expression interval to the date or datetime expression datetime_expr. The unit for interval is given by the unit argument, which should be one of the following values: MICROSECOND (microseconds), SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR. It is possible to use FRAC_SECOND in place of MICROSECOND, but FRAC_SECOND is deprecated. FRAC_SECOND was removed in MySQL 5.5.3. The unit value may be specified using one of keywords as shown, or with a prefix of SQL_TSI_. For example, DAY and SQL_TSI_DAY both are legal. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT TIMESTAMPADD(MINUTE,1,'2003-01-02'); -> '2003-01-02 00:01:00' mysql> SELECT TIMESTAMPADD(WEEK,1,'2003-01-02'); -> '2003-01-09' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html[SHOWSHOW has many forms that provide information about databases, tables, columns, or status information about the server. This section describes those following: SHOW AUTHORS SHOW {BINARY | MASTER} LOGS SHOW BINLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count] SHOW CHARACTER SET [like_or_where] SHOW COLLATION [like_or_where] SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [like_or_where] SHOW CONTRIBUTORS SHOW CREATE DATABASE db_name SHOW CREATE EVENT event_name SHOW CREATE FUNCTION func_name SHOW CREATE PROCEDURE proc_name SHOW CREATE TABLE tbl_name SHOW CREATE TRIGGER trigger_name SHOW CREATE VIEW view_name SHOW DATABASES [like_or_where] SHOW ENGINE engine_name {STATUS | MUTEX} SHOW [STORAGE] ENGINES SHOW ERRORS [LIMIT [offset,] row_count] SHOW EVENTS SHOW FUNCTION CODE func_name SHOW FUNCTION STATUS [like_or_where] SHOW GRANTS FOR user SHOW INDEX FROM tbl_name [FROM db_name] SHOW MASTER STATUS SHOW OPEN TABLES [FROM db_name] [like_or_where] SHOW PLUGINS SHOW PROCEDURE CODE proc_name SHOW PROCEDURE STATUS [like_or_where] SHOW PRIVILEGES SHOW [FULL] PROCESSLIST SHOW PROFILE [types] [FOR QUERY n] [OFFSET n] [LIMIT n] SHOW PROFILES SHOW SLAVE HOSTS SHOW SLAVE STATUS SHOW [GLOBAL | SESSION] STATUS [like_or_where] SHOW TABLE STATUS [FROM db_name] [like_or_where] SHOW [FULL] TABLES [FROM db_name] [like_or_where] SHOW TRIGGERS [FROM db_name] [like_or_where] SHOW [GLOBAL | SESSION] VARIABLES [like_or_where] SHOW WARNINGS [LIMIT [offset,] row_count] like_or_where: LIKE 'pattern' | WHERE expr If the syntax for a given SHOW statement includes a LIKE 'pattern' part, 'pattern' is a string that can contain the SQL "%" and "_" wildcard characters. The pattern is useful for restricting statement output to matching values. Several SHOW statements also accept a WHERE clause that provides more flexibility in specifying which rows to display. See http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show.html 0http://dev.mysql.com/doc/refman/5.5/en/show.html\GREATESTSyntax: GREATEST(value1,value2,...) With two or more arguments, returns the largest (maximum-valued) argument. The arguments are compared using the same rules as for LEAST(). URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT GREATEST(2,0); -> 2 mysql> SELECT GREATEST(34.0,3.0,5.0,767.0); -> 767.0 mysql> SELECT GREATEST('B','A','C'); -> 'C' @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html]SHOW VARIABLESSyntax: SHOW [GLOBAL | SESSION] VARIABLES [LIKE 'pattern' | WHERE expr] SHOW VARIABLES shows the values of MySQL system variables. This information also can be obtained using the mysqladmin variables command. The LIKE clause, if present, indicates which variable names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. This statement does not require any privilege. It requires only the ability to connect to the server. With the GLOBAL modifier, SHOW VARIABLES displays the values that are used for new connections to MySQL. As of MySQL 5.5.3, if a variable has no global value, no value is displayed. Before 5.5.3, the session value is displayed. With SESSION, SHOW VARIABLES displays the values that are in effect for the current connection. If no modifier is present, the default is SESSION. LOCAL is a synonym for SESSION. With a LIKE clause, the statement displays only rows for those variables with names that match the pattern. To obtain the row for a specific variable, use a LIKE clause as shown: SHOW VARIABLES LIKE 'max_join_size'; SHOW SESSION VARIABLES LIKE 'max_join_size'; To get a list of variables whose name match a pattern, use the "%" wildcard character in a LIKE clause: SHOW VARIABLES LIKE '%size%'; SHOW GLOBAL VARIABLES LIKE '%size%'; Wildcard characters can be used in any position within the pattern to be matched. Strictly speaking, because "_" is a wildcard that matches any single character, you should escape it as "\_" to match it literally. In practice, this is rarely necessary. URL: http://dev.mysql.com/doc/refman/5.5/en/show-variables.html :http://dev.mysql.com/doc/refman/5.5/en/show-variables.html^BINLOGSyntax: BINLOG 'str' BINLOG is an internal-use statement. It is generated by the mysqlbinlog program as the printable representation of certain events in binary log files. (See http://dev.mysql.com/doc/refman/5.5/en/mysqlbinlog.html.) The 'str' value is a base 64-encoded string the that server decodes to determine the data change indicated by the corresponding event. This statement requires the SUPER privilege. URL: http://dev.mysql.com/doc/refman/5.5/en/binlog.html 2http://dev.mysql.com/doc/refman/5.5/en/binlog.html_BIT_ANDSyntax: BIT_AND(expr) Returns the bitwise AND of all bits in expr. The calculation is performed with 64-bit (BIGINT) precision. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html`SECONDSyntax: SECOND(time) Returns the second for time, in the range 0 to 59. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html /mysql> SELECT SECOND('10:05:03'); -> 3 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlaATAN20Syntax: ATAN(Y,X), ATAN2(Y,X) Returns the arc tangent of the two variables X and Y. It is similar to calculating the arc tangent of Y / X, except that the signs of both arguments are used to determine the quadrant of the result. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html omysql> SELECT ATAN(-2,2); -> -0.78539816339745 mysql> SELECT ATAN2(PI(),0); -> 1.5707963267949 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlb MBRCONTAINSOMBRContains(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangle of g1 contains the Minimum Bounding Rectangle of g2. This tests the opposite relationship as MBRWithin(). URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr mysql> SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))'); mysql> SET @g2 = GeomFromText('Point(1 1)'); mysql> SELECT MBRContains(@g1,@g2), MBRContains(@g2,@g1); ----------------------+----------------------+ | MBRContains(@g1,@g2) | MBRContains(@g2,@g1) | +----------------------+----------------------+ | 1 | 0 | +----------------------+----------------------+ http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbrcHOUR!Syntax: HOUR(time) Returns the hour for time. The range of the return value is 0 to 23 for time-of-day values. However, the range of TIME values actually is much larger, so HOUR can return values greater than 23. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html ^mysql> SELECT HOUR('10:05:03'); -> 10 mysql> SELECT HOUR('272:59:59'); -> 272 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmldSELECTSyntax: SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr [, select_expr ...] [FROM table_references [WHERE where_condition] [GROUP BY {col_name | expr | position} [ASC | DESC], ... [WITH ROLLUP]] [HAVING where_condition] [ORDER BY {col_name | expr | position} [ASC | DESC], ...] [LIMIT {[offset,] row_count | row_count OFFSET offset}] [PROCEDURE procedure_name(argument_list)] [INTO OUTFILE 'file_name' [CHARACTER SET charset_name] export_options | INTO DUMPFILE 'file_name' | INTO var_name [, var_name]] [FOR UPDATE | LOCK IN SHARE MODE]] SELECT is used to retrieve rows selected from one or more tables, and can include UNION statements and subqueries. See [HELP UNION], and http://dev.mysql.com/doc/refman/5.5/en/subqueries.html. The most commonly used clauses of SELECT statements are these: o Each select_expr indicates a column that you want to retrieve. There must be at least one select_expr. o table_references indicates the table or tables from which to retrieve rows. Its syntax is described in [HELP JOIN]. o The WHERE clause, if given, indicates the condition or conditions that rows must satisfy to be selected. where_condition is an expression that evaluates to true for each row to be selected. The statement selects all rows if there is no WHERE clause. In the WHERE expression, you can use any of the functions and operators that MySQL supports, except for aggregate (summary) functions. See http://dev.mysql.com/doc/refman/5.5/en/expressions.html, and http://dev.mysql.com/doc/refman/5.5/en/functions.html. SELECT can also be used to retrieve rows computed without reference to any table. URL: http://dev.mysql.com/doc/refman/5.5/en/select.html 2http://dev.mysql.com/doc/refman/5.5/en/select.html"eCOTvSyntax: COT(X) Returns the cotangent of X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Ymysql> SELECT COT(12); -> -1.5726734063977 mysql> SELECT COT(0); -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlfSHOW CREATE EVENTrSyntax: SHOW CREATE EVENT event_name This statement displays the CREATE EVENT statement needed to re-create a given event. It requires the EVENT privilege for the database from which the event is to be shown. For example (using the same event e_daily defined and then altered in [HELP SHOW EVENTS]): URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-event.html mysql> SHOW CREATE EVENT test.e_daily\G *************************** 1. row *************************** Event: e_daily sql_mode: time_zone: SYSTEM Create Event: CREATE EVENT `e_daily` ON SCHEDULE EVERY 1 DAY STARTS CURRENT_TIMESTAMP + INTERVAL 6 HOUR ON COMPLETION NOT PRESERVE ENABLE COMMENT 'Saves total number of sessions then clears the table each day' DO BEGIN INSERT INTO site_activity.totals (time, total) SELECT CURRENT_TIMESTAMP, COUNT(*) FROM site_activity.sessions; DELETE FROM site_activity.sessions; END character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci =http://dev.mysql.com/doc/refman/5.5/en/show-create-event.htmlg LOAD_FILE%Syntax: LOAD_FILE(file_name) Reads the file and returns the file contents as a string. To use this function, the file must be located on the server host, you must specify the full path name to the file, and you must have the FILE privilege. The file must be readable by all and its size less than max_allowed_packet bytes. If the secure_file_priv system variable is set to a nonempty directory name, the file to be loaded must be located in that directory. If the file does not exist or cannot be read because one of the preceding conditions is not satisfied, the function returns NULL. The character_set_filesystem system variable controls interpretation of file names that are given as literal strings. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html [mysql> UPDATE t SET blob_col=LOAD_FILE('/tmp/picture') WHERE id=1; <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html&h POINTFROMTEXTPointFromText(wkt[,srid]) Constructs a POINT value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functionsi GROUP_CONCATSyntax: GROUP_CONCAT(expr) This function returns a string result with the concatenated non-NULL values from a group. It returns NULL if there are no non-NULL values. The full syntax is as follows: GROUP_CONCAT([DISTINCT] expr [,expr ...] [ORDER BY {unsigned_integer | col_name | expr} [ASC | DESC] [,col_name ...]] [SEPARATOR str_val]) URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html zmysql> SELECT student_name, -> GROUP_CONCAT(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlQj DATE_FORMATSyntax: DATE_FORMAT(date,format) Formats the date value according to the format string. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Qmysql> SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y'); -> 'Sunday October 2009' mysql> SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s'); -> '22:23:00' mysql> SELECT DATE_FORMAT('1900-10-04 22:23:00', -> '%D %y %a %d %m %b %j'); -> '4th 00 Thu 04 10 Oct 277' mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00', -> '%H %k %I %r %T %S %w'); -> '22 22 10 10:23:00 PM 22:23:00 00 6' mysql> SELECT DATE_FORMAT('1999-01-01', '%X %V'); -> '1998 52' mysql> SELECT DATE_FORMAT('2006-06-00', '%d'); -> '00' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlk BENCHMARKnSyntax: BENCHMARK(count,expr) The BENCHMARK() function executes the expression expr repeatedly count times. It may be used to time how quickly MySQL processes the expression. The result value is always 0. The intended use is from within the mysql client, which reports query execution times: URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html Imysql> SELECT BENCHMARK(1000000,ENCODE('hello','goodbye')); +----------------------------------------------+ | BENCHMARK(1000000,ENCODE('hello','goodbye')) | +----------------------------------------------+ | 0 | +----------------------------------------------+ 1 row in set (4.74 sec) Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html6lYEARSyntax: YEAR(date) Returns the year for date, in the range 1000 to 9999, or 0 for the "zero" date. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 2mysql> SELECT YEAR('1987-01-01'); -> 1987 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlm SHOW ENGINEYSyntax: SHOW ENGINE engine_name {STATUS | MUTEX} SHOW ENGINE displays operational information about a storage engine. The following statements currently are supported: SHOW ENGINE INNODB STATUS SHOW ENGINE INNODB MUTEX SHOW ENGINE {NDB | NDBCLUSTER} STATUS SHOW ENGINE PERFORMANCE_SCHEMA STATUS SHOW ENGINE INNODB STATUS displays extensive information from the standard InnoDB Monitor about the state of the InnoDB storage engine. For information about the standard monitor and other InnoDB Monitors that provide information about InnoDB processing, see http://dev.mysql.com/doc/refman/5.5/en/innodb-monitors.html. SHOW ENGINE INNODB MUTEX displays InnoDB mutex statistics. The statement displays the following fields: o Type Always InnoDB. o Name The source file where the mutex is implemented, and the line number in the file where the mutex is created. The line number may change depending on your version of MySQL. o Status The mutex status. This field displays several values if UNIV_DEBUG was defined at MySQL compilation time (for example, in include/univ.i in the InnoDB part of the MySQL source tree). If UNIV_DEBUG was not defined, the statement displays only the os_waits value. In the latter case (without UNIV_DEBUG), the information on which the output is based is insufficient to distinguish regular mutexes and mutexes that protect rw-locks (which permit multiple readers or a single writer). Consequently, the output may appear to contain multiple rows for the same mutex. o count indicates how many times the mutex was requested. o spin_waits indicates how many times the spinlock had to run. o spin_rounds indicates the number of spinlock rounds. (spin_rounds divided by spin_waits provides the average round count.) o os_waits indicates the number of operating system waits. This occurs when the spinlock did not work (the mutex was not locked during the spinlock and it was necessary to yield to the operating system and wait). o os_yields indicates the number of times a the thread trying to lock a mutex gave up its timeslice and yielded to the operating system (on the presumption that permitting other threads to run will free the mutex so that it can be locked). o os_wait_times indicates the amount of time (in ms) spent in operating system waits, if the timed_mutexes system variable is 1 (ON). If timed_mutexes is 0 (OFF), timing is disabled, so os_wait_times is 0. timed_mutexes is off by default. Information from this statement can be used to diagnose system problems. For example, large values of spin_waits and spin_rounds may indicate scalability problems. Use SHOW ENGINE PERFORMANCE_SCHEMA STATUS to inspect the internal operation of the Performance Schema code: mysql> SHOW ENGINE PERFORMANCE_SCHEMA STATUS\G ... *************************** 3. row *************************** Type: performance_schema Name: events_waits_history.row_size Status: 76 *************************** 4. row *************************** Type: performance_schema Name: events_waits_history.row_count Status: 10000 *************************** 5. row *************************** Type: performance_schema Name: events_waits_history.memory Status: 760000 ... *************************** 57. row *************************** Type: performance_schema Name: performance_schema.memory Status: 26459600 ... The intent of this statement is to help the DBA to understand the effects that different options have on memory requirements. Name values consist of two parts, which name an internal buffer and an attribute of the buffer, respectively: o Internal buffers that are exposed as a table in the performance_schema database are named after the table. Examples: events_waits_history.row_size, mutex_instances.row_count. o Internal buffers that are not exposed as a table are named within parentheses. Examples: (pfs_cond_class).row_size, (pfs_mutex_class).memory. o Values that apply to the Performance Schema as a whole begin with performance_schema. Example: performance_schema.memory. Attributes have these meanings: o row_size cannot be changed. It is the size of the internal record used by the implementation. o row_count can be changed depending on the configuration options. o For a table, tbl_name.memory is the product of row_size multiplied by row_count. For the Performance Schema as a whole, performance_schema.memory is the sum of all the memory used (the sum of all other memory values). In some cases, there is a direct relationship between a configuration parameter and a SHOW ENGINE value. For example, events_waits_history_long.row_count corresponds to performance_schema_events_waits_history_long_size. In other cases, the relationship is more complex. For example, events_waits_history.row_count corresponds to performance_schema_events_waits_history_size (the number of rows per thread) multiplied by performance_schema_max_thread_instances ( the number of threads). If the server has the NDBCLUSTER storage engine enabled, SHOW ENGINE NDB STATUS displays cluster status information such as the number of connected data nodes, the cluster connectstring, and cluster binlog epochs, as well as counts of various Cluster API objects created by the MySQL Server when connected to the cluster. Sample output from this statement is shown here: mysql> SHOW ENGINE NDB STATUS; +------------+-----------------------+--------------------------------------------------+ | Type | Name | Status | +------------+-----------------------+--------------------------------------------------+ | ndbcluster | connection | cluster_node_id=7, connected_host=192.168.0.103, connected_port=1186, number_of_data_nodes=4, number_of_ready_data_nodes=3, connect_count=0 | | ndbcluster | NdbTransaction | created=6, free=0, sizeof=212 | | ndbcluster | NdbOperation | created=8, free=8, sizeof=660 | | ndbcluster | NdbIndexScanOperation | created=1, free=1, sizeof=744 | | ndbcluster | NdbIndexOperation | created=0, free=0, sizeof=664 | | ndbcluster | NdbRecAttr | created=1285, free=1285, sizeof=60 | | ndbcluster | NdbApiSignal | created=16, free=16, sizeof=136 | | ndbcluster | NdbLabel | created=0, free=0, sizeof=196 | | ndbcluster | NdbBranch | created=0, free=0, sizeof=24 | | ndbcluster | NdbSubroutine | created=0, free=0, sizeof=68 | | ndbcluster | NdbCall | created=0, free=0, sizeof=16 | | ndbcluster | NdbBlob | created=1, free=1, sizeof=264 | | ndbcluster | NdbReceiver | created=4, free=0, sizeof=68 | | ndbcluster | binlog | latest_epoch=155467, latest_trans_epoch=148126, latest_received_binlog_epoch=0, latest_handled_binlog_epoch=0, latest_applied_binlog_epoch=0 | +------------+-----------------------+--------------------------------------------------+ The rows with connection and binlog in the Name column were added to the output of this statement in MySQL 5.1. The Status column in each of these rows provides information about the MySQL server's connection to the cluster and about the cluster binary log's status, respectively. The Status information is in the form of comma-delimited set of name/value pairs. URL: http://dev.mysql.com/doc/refman/5.5/en/show-engine.html 7http://dev.mysql.com/doc/refman/5.5/en/show-engine.htmln NAME_CONSThSyntax: NAME_CONST(name,value) Returns the given value. When used to produce a result set column, NAME_CONST() causes the column to have the given name. The arguments should be constants. mysql> SELECT NAME_CONST('myname', 14); +--------+ | myname | +--------+ | 14 | +--------+ URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlro RELEASE_LOCKSyntax: RELEASE_LOCK(str) Releases the lock named by the string str that was obtained with GET_LOCK(). Returns 1 if the lock was released, 0 if the lock was not established by this thread (in which case the lock is not released), and NULL if the named lock did not exist. The lock does not exist if it was never obtained by a call to GET_LOCK() or if it has previously been released. The DO statement is convenient to use with RELEASE_LOCK(). See [HELP DO]. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlpIS NULLxSyntax: IS NULL Tests whether a value is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html Emysql> SELECT 1 IS NULL, 0 IS NULL, NULL IS NULL; -> 0, 0, 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlq CONVERT_TZSyntax: CONVERT_TZ(dt,from_tz,to_tz) CONVERT_TZ() converts a datetime value dt from the time zone given by from_tz to the time zone given by to_tz and returns the resulting value. Time zones are specified as described in http://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html. This function returns NULL if the arguments are invalid. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET'); -> '2004-01-01 13:00:00' mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00'); -> '2004-01-01 22:00:00' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlbr TIME_TO_SECSyntax: TIME_TO_SEC(time) Returns the time argument, converted to seconds. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html omysql> SELECT TIME_TO_SEC('22:23:00'); -> 80580 mysql> SELECT TIME_TO_SEC('00:39:38'); -> 2378 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlusWEEKDAYSyntax: WEEKDAY(date) Returns the weekday index for date (0 = Monday, 1 = Tuesday, ... 6 = Sunday). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mmysql> SELECT WEEKDAY('2008-02-03 22:23:00'); -> 6 mysql> SELECT WEEKDAY('2007-11-06'); -> 1 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlt EXPORT_SET%Syntax: EXPORT_SET(bits,on,off[,separator[,number_of_bits]]) Returns a string such that for every bit set in the value bits, you get an on string and for every bit not set in the value, you get an off string. Bits in bits are examined from right to left (from low-order to high-order bits). Strings are added to the result from left to right, separated by the separator string (the default being the comma character ","). The number of bits examined is given by number_of_bits, which has a default of 64 if not specified. number_of_bits is silently clipped to 64 if larger than 64. It is treated as an unsigned integer, so a value of -1 is effectively the same as 64. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT EXPORT_SET(5,'Y','N',',',4); -> 'Y,N,Y,N' mysql> SELECT EXPORT_SET(6,'1','0',',',10); -> '0,1,1,0,0,0,0,0,0,0' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html u ALTER SERVER'Syntax: ALTER SERVER server_name OPTIONS (option [, option] ...) Alters the server information for server_name, adjusting any of the options permitted in the CREATE SERVER statement. See [HELP CREATE SERVER]. The corresponding fields in the mysql.servers table are updated accordingly. This statement requires the SUPER privilege. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-server.html 'ALTER SERVER s OPTIONS (USER 'sally'); 8http://dev.mysql.com/doc/refman/5.5/en/alter-server.htmlpvRESIGNAL(Syntax: RESIGNAL [condition_value] [SET signal_information_item [, signal_information_item] ...] condition_value: SQLSTATE [VALUE] sqlstate_value | condition_name signal_information_item: condition_information_item_name = simple_value_specification condition_information_item_name: CLASS_ORIGIN | SUBCLASS_ORIGIN | MESSAGE_TEXT | MYSQL_ERRNO | CONSTRAINT_CATALOG | CONSTRAINT_SCHEMA | CONSTRAINT_NAME | CATALOG_NAME | SCHEMA_NAME | TABLE_NAME | COLUMN_NAME | CURSOR_NAME condition_name, simple_value_specification: (see following discussion) RESIGNAL passes on the error condition information that is available during execution of a condition handler within a compound statement inside a stored procedure or function, trigger, or event. RESIGNAL may change some or all information before passing it on. RESIGNAL is related to SIGNAL, but instead of originating a condition as SIGNAL does, RESIGNAL relays existing condition information, possibly after modifying it. RESIGNAL makes it possible to both handle an error and return the error information. Otherwise, by executing an SQL statement within the handler, information that caused the handler's activation is destroyed. RESIGNAL also can make some procedures shorter if a given handler can handle part of a situation, then pass the condition "up the line" to another handler. No special privileges are required to execute the RESIGNAL statement. For condition_value and signal_information_item, the definitions and rules are the same for RESIGNAL as for SIGNAL (see [HELP SIGNAL]). The RESIGNAL statement takes condition_value and SET clauses, both of which are optional. This leads to several possible uses: o RESIGNAL alone: RESIGNAL; o RESIGNAL with new signal information: RESIGNAL SET signal_information_item [, signal_information_item] ...; o RESIGNAL with a condition value and possibly new signal information: RESIGNAL condition_value [SET signal_information_item [, signal_information_item] ...]; URL: http://dev.mysql.com/doc/refman/5.5/en/resignal.html 4http://dev.mysql.com/doc/refman/5.5/en/resignal.htmlw TIME FUNCTIONSyntax: TIME(expr) Extracts the time part of the time or datetime expression expr and returns it as a string. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT TIME('2003-12-31 01:02:03'); -> '01:02:03' mysql> SELECT TIME('2003-12-31 01:02:03.000123'); -> '01:02:03.000123' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlxDATE_ADDSyntax: DATE_ADD(date,INTERVAL expr unit), DATE_SUB(date,INTERVAL expr unit) These functions perform date arithmetic. The date argument specifies the starting date or datetime value. expr is an expression specifying the interval value to be added or subtracted from the starting date. expr is a string; it may start with a "-" for negative intervals. unit is a keyword indicating the units in which the expression should be interpreted. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Umysql> SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND; -> '2009-01-01 00:00:00' mysql> SELECT INTERVAL 1 DAY + '2008-12-31'; -> '2009-01-01' mysql> SELECT '2005-01-01' - INTERVAL 1 SECOND; -> '2004-12-31 23:59:59' mysql> SELECT DATE_ADD('2000-12-31 23:59:59', -> INTERVAL 1 SECOND); -> '2001-01-01 00:00:00' mysql> SELECT DATE_ADD('2010-12-31 23:59:59', -> INTERVAL 1 DAY); -> '2011-01-01 23:59:59' mysql> SELECT DATE_ADD('2100-12-31 23:59:59', -> INTERVAL '1:1' MINUTE_SECOND); -> '2101-01-01 00:01:00' mysql> SELECT DATE_SUB('2005-01-01 00:00:00', -> INTERVAL '1 1:1:1' DAY_SECOND); -> '2004-12-30 22:58:59' mysql> SELECT DATE_ADD('1900-01-01 00:00:00', -> INTERVAL '-1 10' DAY_HOUR); -> '1899-12-30 14:00:00' mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY); -> '1997-12-02' mysql> SELECT DATE_ADD('1992-12-31 23:59:59.000002', -> INTERVAL '1.999999' SECOND_MICROSECOND); -> '1993-01-01 00:00:01.000001' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlZyCAST%Syntax: CAST(expr AS type) The CAST() function takes an expression of any type and produces a result value of a specified type, similar to CONVERT(). See the description of CONVERT() for more information. URL: http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html :http://dev.mysql.com/doc/refman/5.5/en/cast-functions.htmlz SOUNDS LIKE%Syntax: expr1 SOUNDS LIKE expr2 This is the same as SOUNDEX(expr1) = SOUNDEX(expr2). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html{ PERIOD_DIFFSyntax: PERIOD_DIFF(P1,P2) Returns the number of months between periods P1 and P2. P1 and P2 should be in the format YYMM or YYYYMM. Note that the period arguments P1 and P2 are not date values. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 8mysql> SELECT PERIOD_DIFF(200802,200703); -> 11 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlB|LIKE%Syntax: expr LIKE pat [ESCAPE 'escape_char'] Pattern matching using SQL simple regular expression comparison. Returns 1 (TRUE) or 0 (FALSE). If either expr or pat is NULL, the result is NULL. The pattern need not be a literal string. For example, it can be specified as a string expression or table column. URL: http://dev.mysql.com/doc/refman/5.5/en/string-comparison-functions.html emysql> SELECT 'David!' LIKE 'David_'; -> 1 mysql> SELECT 'David!' LIKE '%D%v%'; -> 1 Ghttp://dev.mysql.com/doc/refman/5.5/en/string-comparison-functions.html9} MULTIPOINTMultiPoint(pt1,pt2,...) Constructs a MultiPoint value using Point or WKB Point arguments. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions~>>}Syntax: >> Shifts a longlong (BIGINT) number to the right. URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html #mysql> SELECT 4 >> 2; -> 1 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html#FETCHSyntax: FETCH [[NEXT] FROM] cursor_name INTO var_name [, var_name] ... This statement fetches the next row for the SELECT statement associated with the specified cursor (which must be open), and advances the cursor pointer. If a row exists, the fetched columns are stored in the named variables. The number of columns retrieved by the SELECT statement must match the number of output variables specified in the FETCH statement. If no more rows are available, a No Data condition occurs with SQLSTATE value '02000'. To detect this condition, you can set up a handler for it (or for a NOT FOUND condition). For an example, see http://dev.mysql.com/doc/refman/5.5/en/cursors.html. URL: http://dev.mysql.com/doc/refman/5.5/en/fetch.html 1http://dev.mysql.com/doc/refman/5.5/en/fetch.htmlAVGSyntax: AVG([DISTINCT] expr) Returns the average value of expr. The DISTINCT option can be used to return the average of the distinct values of expr. AVG() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html lmysql> SELECT student_name, AVG(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlJ TRUE FALSEThe constants TRUE and FALSE evaluate to 1 and 0, respectively. The constant names can be written in any lettercase. mysql> SELECT TRUE, true, FALSE, false; -> 1, 1, 0, 0 URL: http://dev.mysql.com/doc/refman/5.5/en/boolean-literals.html <http://dev.mysql.com/doc/refman/5.5/en/boolean-literals.html MBRWITHINPMBRWithin(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangle of g1 is within the Minimum Bounding Rectangle of g2. This tests the opposite relationship as MBRContains(). URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr mysql> SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))'); mysql> SET @g2 = GeomFromText('Polygon((0 0,0 5,5 5,5 0,0 0))'); mysql> SELECT MBRWithin(@g1,@g2), MBRWithin(@g2,@g1); +--------------------+--------------------+ | MBRWithin(@g1,@g2) | MBRWithin(@g2,@g1) | +--------------------+--------------------+ | 1 | 0 | +--------------------+--------------------+ http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#relations-on-geometry-mbr SESSION_USERSyntax: SESSION_USER() SESSION_USER() is a synonym for USER(). URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.htmlINFSyntax: expr IN (value,...) Returns 1 if expr is equal to any of the values in the IN list, else returns 0. If all values are constants, they are evaluated according to the type of expr and sorted. The search for the item then is done using a binary search. This means IN is very quick if the IN value list consists entirely of constants. Otherwise, type conversion takes place according to the rules described in http://dev.mysql.com/doc/refman/5.5/en/type-conversion.html, but applied to all the arguments. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html hmysql> SELECT 2 IN (0,3,5,7); -> 0 mysql> SELECT 'wefwf' IN ('wee','wefwf','weg'); -> 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlQUOTE%Syntax: QUOTE(str) Quotes a string to produce a result that can be used as a properly escaped data value in an SQL statement. The string is returned enclosed by single quotation marks and with each instance of backslash ("\"), single quote ("'"), ASCII NUL, and Control+Z preceded by a backslash. If the argument is NULL, the return value is the word "NULL" without enclosing single quotation marks. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html `mysql> SELECT QUOTE('Don\'t!'); -> 'Don\'t!' mysql> SELECT QUOTE(NULL); -> NULL <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlG HELP COMMANDSyntax: mysql> help search_string If you provide an argument to the help command, mysql uses it as a search string to access server-side help from the contents of the MySQL Reference Manual. The proper operation of this command requires that the help tables in the mysql database be initialized with help topic information (see http://dev.mysql.com/doc/refman/5.5/en/server-side-help-support.html). If there is no match for the search string, the search fails: mysql> help me Nothing found Please try to run 'help contents' for a list of all accessible topics Use help contents to see a list of the help categories: mysql> help contents You asked for help about help category: "Contents" For more information, type 'help ', where is one of the following categories: Account Management Administration Data Definition Data Manipulation Data Types Functions Functions and Modifiers for Use with GROUP BY Geographic Features Language Structure Plugins Storage Engines Stored Routines Table Maintenance Transactions Triggers If the search string matches multiple items, mysql shows a list of matching topics: mysql> help logs Many help items for your request exist. To make a more specific request, please type 'help ', where is one of the following topics: SHOW SHOW BINARY LOGS SHOW ENGINE SHOW LOGS Use a topic as the search string to see the help entry for that topic: mysql> help show binary logs Name: 'SHOW BINARY LOGS' Description: Syntax: SHOW BINARY LOGS SHOW MASTER LOGS Lists the binary log files on the server. This statement is used as part of the procedure described in [purge-binary-logs], that shows how to determine which logs can be purged. mysql> SHOW BINARY LOGS; +---------------+-----------+ | Log_name | File_size | +---------------+-----------+ | binlog.000015 | 724935 | | binlog.000016 | 733481 | +---------------+-----------+ URL: http://dev.mysql.com/doc/refman/5.5/en/mysql-server-side-help.html Bhttp://dev.mysql.com/doc/refman/5.5/en/mysql-server-side-help.html+QUARTERSyntax: QUARTER(date) Returns the quarter of the year for date, in the range 1 to 4. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 2mysql> SELECT QUARTER('2008-04-01'); -> 2 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlPOSITION%Syntax: POSITION(substr IN str) POSITION(substr IN str) is a synonym for LOCATE(substr,str). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html?SHOW CREATE FUNCTIONSyntax: SHOW CREATE FUNCTION func_name This statement is similar to SHOW CREATE PROCEDURE but for stored functions. See [HELP SHOW CREATE PROCEDURE]. URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-function.html @http://dev.mysql.com/doc/refman/5.5/en/show-create-function.htmlk IS_USED_LOCKSyntax: IS_USED_LOCK(str) Checks whether the lock named str is in use (that is, locked). If so, it returns the connection identifier of the client that holds the lock. Otherwise, it returns NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlC POLYFROMTEXTPolyFromText(wkt[,srid]), PolygonFromText(wkt[,srid]) Constructs a POLYGON value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions DES_ENCRYPT Syntax: DES_ENCRYPT(str[,{key_num|key_str}]) Encrypts the string with the given key using the Triple-DES algorithm. This function works only if MySQL has been configured with SSL support. See http://dev.mysql.com/doc/refman/5.5/en/ssl-connections.html. The encryption key to use is chosen based on the second argument to DES_ENCRYPT(), if one was given. With no argument, the first key from the DES key file is used. With a key_num argument, the given key number (0 to 9) from the DES key file is used. With a key_str argument, the given key string is used to encrypt str. The key file can be specified with the --des-key-file server option. The return string is a binary string where the first character is CHAR(128 | key_num). If an error occurs, DES_ENCRYPT() returns NULL. The 128 is added to make it easier to recognize an encrypted key. If you use a string key, key_num is 127. The string length for the result is given by this formula: new_len = orig_len + (8 - (orig_len % 8)) + 1 Each line in the DES key file has the following format: key_num des_key_str Each key_num value must be a number in the range from 0 to 9. Lines in the file may be in any order. des_key_str is the string that is used to encrypt the message. There should be at least one space between the number and the key. The first key is the default key that is used if you do not specify any key argument to DES_ENCRYPT(). You can tell MySQL to read new key values from the key file with the FLUSH DES_KEY_FILE statement. This requires the RELOAD privilege. One benefit of having a set of default keys is that it gives applications a way to check for the existence of encrypted column values, without giving the end user the right to decrypt those values. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html zmysql> SELECT customer_address FROM customer_table > WHERE crypted_credit_card = DES_ENCRYPT('credit_card_number'); @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlCEIL~Syntax: CEIL(X) CEIL() is a synonym for CEILING(). URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlLENGTH%9Syntax: LENGTH(str) Returns the length of the string str, measured in bytes. A multi-byte character counts as multiple bytes. This means that for a string containing five 2-byte characters, LENGTH() returns 10, whereas CHAR_LENGTH() returns 5. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html +mysql> SELECT LENGTH('text'); -> 4 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html STR_TO_DATESyntax: STR_TO_DATE(str,format) This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts. If the date, time, or datetime value extracted from str is illegal, STR_TO_DATE() returns NULL and produces a warning. The server scans str attempting to match format to it. The format string can contain literal characters and format specifiers beginning with %. Literal characters in format must match literally in str. Format specifiers in format must match a date or time part in str. For the specifiers that can be used in format, see the DATE_FORMAT() function description. mysql> SELECT STR_TO_DATE('01,5,2013','%d,%m,%Y'); -> '2013-05-01' mysql> SELECT STR_TO_DATE('May 1, 2013','%M %d,%Y'); -> '2013-05-01' Scanning starts at the beginning of str and fails if format is found not to match. Extra characters at the end of str are ignored. mysql> SELECT STR_TO_DATE('a09:30:17','a%h:%i:%s'); -> '09:30:17' mysql> SELECT STR_TO_DATE('a09:30:17','%h:%i:%s'); -> NULL mysql> SELECT STR_TO_DATE('09:30:17a','%h:%i:%s'); -> '09:30:17' Unspecified date or time parts have a value of 0, so incompletely specified values in str produce a result with some or all parts set to 0: mysql> SELECT STR_TO_DATE('abc','abc'); -> '0000-00-00' mysql> SELECT STR_TO_DATE('9','%m'); -> '0000-09-00' mysql> SELECT STR_TO_DATE('9','%s'); -> '00:00:09' URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlY Y(p) Returns the Y-coordinate value for the Point object p as a double-precision number. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#point-property-functions mysql> SELECT Y(POINT(56.7, 53.34)); +-----------------------+ | Y(POINT(56.7, 53.34)) | +-----------------------+ | 53.34 | +-----------------------+ `http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#point-property-functionseCHECKSUM TABLESyntax: CHECKSUM TABLE tbl_name [, tbl_name] ... [ QUICK | EXTENDED ] CHECKSUM TABLE reports a table checksum. This statement requires the SELECT privilege for the table. With QUICK, the live table checksum is reported if it is available, or NULL otherwise. This is very fast. A live checksum is enabled by specifying the CHECKSUM=1 table option when you create the table; currently, this is supported only for MyISAM tables. See [HELP CREATE TABLE]. With EXTENDED, the entire table is read row by row and the checksum is calculated. This can be very slow for large tables. If neither QUICK nor EXTENDED is specified, MySQL returns a live checksum if the table storage engine supports it and scans the table otherwise. For a nonexistent table, CHECKSUM TABLE returns NULL and generates a warning. In MySQL 5.5, CHECKSUM TABLE returns 0 for partitioned tables unless you include the EXTENDED option. This issue is resolved in MySQL 5.6. (Bug #11933226, Bug #60681) The checksum value depends on the table row format. If the row format changes, the checksum also changes. For example, the storage format for VARCHAR changed between MySQL 4.1 and 5.0, so if a 4.1 table is upgraded to MySQL 5.0, the checksum value may change. URL: http://dev.mysql.com/doc/refman/5.5/en/checksum-table.html :http://dev.mysql.com/doc/refman/5.5/en/checksum-table.htmlNUMINTERIORRINGSNumInteriorRings(poly) Returns the number of interior rings in the Polygon value poly. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functions Ymysql> SET @poly = -> 'Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'; mysql> SELECT NumInteriorRings(GeomFromText(@poly)); +---------------------------------------+ | NumInteriorRings(GeomFromText(@poly)) | +---------------------------------------+ | 1 | +---------------------------------------+ bhttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functions INTERIORRINGNInteriorRingN(poly,N) Returns the N-th interior ring for the Polygon value poly as a LineString. Rings are numbered beginning with 1. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functions mysql> SET @poly = -> 'Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'; mysql> SELECT AsText(InteriorRingN(GeomFromText(@poly),1)); +----------------------------------------------+ | AsText(InteriorRingN(GeomFromText(@poly),1)) | +----------------------------------------------+ | LINESTRING(1 1,1 2,2 2,2 1,1 1) | +----------------------------------------------+ bhttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#polygon-property-functionsUTC_TIMESyntax: UTC_TIME, UTC_TIME() Returns the current UTC time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Omysql> SELECT UTC_TIME(), UTC_TIME() + 0; -> '18:07:53', 180753.000000 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html DROP FUNCTION'LThe DROP FUNCTION statement is used to drop stored functions and user-defined functions (UDFs): o For information about dropping stored functions, see [HELP DROP PROCEDURE]. o For information about dropping user-defined functions, see [HELP DROP FUNCTION UDF]. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-function.html 9http://dev.mysql.com/doc/refman/5.5/en/drop-function.htmlX ALTER EVENT' Syntax: ALTER [DEFINER = { user | CURRENT_USER }] EVENT event_name [ON SCHEDULE schedule] [ON COMPLETION [NOT] PRESERVE] [RENAME TO new_event_name] [ENABLE | DISABLE | DISABLE ON SLAVE] [COMMENT 'comment'] [DO event_body] The ALTER EVENT statement changes one or more of the characteristics of an existing event without the need to drop and recreate it. The syntax for each of the DEFINER, ON SCHEDULE, ON COMPLETION, COMMENT, ENABLE / DISABLE, and DO clauses is exactly the same as when used with CREATE EVENT. (See [HELP CREATE EVENT].) Any user can alter an event defined on a database for which that user has the EVENT privilege. When a user executes a successful ALTER EVENT statement, that user becomes the definer for the affected event. ALTER EVENT works only with an existing event: mysql> ALTER EVENT no_such_event > ON SCHEDULE > EVERY '2:3' DAY_HOUR; ERROR 1517 (HY000): Unknown event 'no_such_event' URL: http://dev.mysql.com/doc/refman/5.5/en/alter-event.html 7http://dev.mysql.com/doc/refman/5.5/en/alter-event.htmlSTDDEV@Syntax: STDDEV(expr) Returns the population standard deviation of expr. This function is provided for compatibility with Oracle. The standard SQL function STDDEV_POP() can be used instead. This function returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlDATE_SUBSyntax: DATE_SUB(date,INTERVAL expr unit) See the description for DATE_ADD(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html PERIOD_ADDSyntax: PERIOD_ADD(P,N) Adds N months to period P (in the format YYMM or YYYYMM). Returns a value in the format YYYYMM. Note that the period argument P is not a date value. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 6mysql> SELECT PERIOD_ADD(200801,2); -> 200803 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html|XSyntax: | Bitwise OR: URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html %mysql> SELECT 29 | 15; -> 31 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.htmlQ GEOMFROMTEXTGeomFromText(wkt[,srid]), GeometryFromText(wkt[,srid]) Constructs a geometry value of any type using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions UUID_SHORT#Syntax: UUID_SHORT() Returns a "short" universal identifier as a 64-bit unsigned integer (rather than a string-form 128-bit identifier as returned by the UUID() function). The value of UUID_SHORT() is guaranteed to be unique if the following conditions hold: o The server_id of the current host is unique among your set of master and slave servers o server_id is between 0 and 255 o You do not set back your system time for your server between mysqld restarts o You do not invoke UUID_SHORT() on average more than 16 million times per second between mysqld restarts The UUID_SHORT() return value is constructed this way: (server_id & 255) << 56 + (server_startup_time_in_seconds << 24) + incremented_variable++; URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html 9mysql> SELECT UUID_SHORT(); -> 92395783831158784 Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html=RIGHT%Syntax: RIGHT(str,len) Returns the rightmost len characters from the string str, or NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 7mysql> SELECT RIGHT('foobarbar', 4); -> 'rbar' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html'DATEDIFF:Syntax: DATEDIFF(expr1,expr2) DATEDIFF() returns expr1 - expr2 expressed as a value in days from one date to the other. expr1 and expr2 are date or date-and-time expressions. Only the date parts of the values are used in the calculation. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30'); -> 1 mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31'); -> -31 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlvDROP TABLESPACE' Syntax: DROP TABLESPACE tablespace_name ENGINE [=] engine_name This statement drops a tablespace that was previously created using CREATE TABLESPACE (see [HELP CREATE TABLESPACE]). *Important*: The tablespace to be dropped must not contain any data files; in other words, before you can drop a tablespace, you must first drop each of its data files using ALTER TABLESPACE ... DROP DATAFILE (see [HELP ALTER TABLESPACE]). The ENGINE clause (required) specifies the storage engine used by the tablespace. Currently, the only accepted values for engine_name are NDB and NDBCLUSTER. DROP TABLESPACE is useful only with Disk Data storage for MySQL Cluster. See http://dev.mysql.com/doc/refman/5.5/en/mysql-cluster-disk-data.html. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-tablespace.html ;http://dev.mysql.com/doc/refman/5.5/en/drop-tablespace.htmljDROP PROCEDURE'Syntax: DROP {PROCEDURE | FUNCTION} [IF EXISTS] sp_name This statement is used to drop a stored procedure or function. That is, the specified routine is removed from the server. You must have the ALTER ROUTINE privilege for the routine. (If the automatic_sp_privileges system variable is enabled, that privilege and EXECUTE are granted automatically to the routine creator when the routine is created and dropped from the creator when the routine is dropped. See http://dev.mysql.com/doc/refman/5.5/en/stored-routines-privileges.html. ) The IF EXISTS clause is a MySQL extension. It prevents an error from occurring if the procedure or function does not exist. A warning is produced that can be viewed with SHOW WARNINGS. URL: http://dev.mysql.com/doc/refman/5.5/en/drop-procedure.html :http://dev.mysql.com/doc/refman/5.5/en/drop-procedure.htmll CHECK TABLESyntax: CHECK TABLE tbl_name [, tbl_name] ... [option] ... option = {FOR UPGRADE | QUICK | FAST | MEDIUM | EXTENDED | CHANGED} CHECK TABLE checks a table or tables for errors. CHECK TABLE works for InnoDB, MyISAM, ARCHIVE, and CSV tables. For MyISAM tables, the key statistics are updated as well. To check a table, you must have some privilege for it. CHECK TABLE can also check views for problems, such as tables that are referenced in the view definition that no longer exist. CHECK TABLE is supported for partitioned tables, and you can use ALTER TABLE ... CHECK PARTITION to check one or more partitions; for more information, see [HELP ALTER TABLE], and http://dev.mysql.com/doc/refman/5.5/en/partitioning-maintenance.html. URL: http://dev.mysql.com/doc/refman/5.5/en/check-table.html 7http://dev.mysql.com/doc/refman/5.5/en/check-table.htmljBIN%Syntax: BIN(N) Returns a string representation of the binary value of N, where N is a longlong (BIGINT) number. This is equivalent to CONV(N,10,2). Returns NULL if N is NULL. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html )mysql> SELECT BIN(12); -> '1100' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html MINSTALL PLUGIN Syntax: INSTALL PLUGIN plugin_name SONAME 'shared_library_name' This statement installs a server plugin. It requires the INSERT privilege for the mysql.plugin table. plugin_name is the name of the plugin as defined in the plugin descriptor structure contained in the library file (see http://dev.mysql.com/doc/refman/5.5/en/plugin-data-structures.html). Plugin names are not case sensitive. For maximal compatibility, plugin names should be limited to ASCII letters, digits, and underscore because they are used in C source files, shell command lines, M4 and Bourne shell scripts, and SQL environments. shared_library_name is the name of the shared library that contains the plugin code. The name includes the file name extension (for example, libmyplugin.so, libmyplugin.dll, or libmyplugin.dylib). The shared library must be located in the plugin directory (the directory named by the plugin_dir system variable). The library must be in the plugin directory itself, not in a subdirectory. By default, plugin_dir is the plugin directory under the directory named by the pkglibdir configuration variable, but it can be changed by setting the value of plugin_dir at server startup. For example, set its value in a my.cnf file: [mysqld] plugin_dir=/path/to/plugin/directory If the value of plugin_dir is a relative path name, it is taken to be relative to the MySQL base directory (the value of the basedir system variable). INSTALL PLUGIN loads and initializes the plugin code to make the plugin available for use. A plugin is initialized by executing its initialization function, which handles any setup that the plugin must perform before it can be used. When the server shuts down, it executes the deinitialization function for each plugin that is loaded so that the plugin has a change to perform any final cleanup. INSTALL PLUGIN also registers the plugin by adding a line that indicates the plugin name and library file name to the mysql.plugin table. At server startup, the server loads and initializes any plugin that is listed in the mysql.plugin table. This means that a plugin is installed with INSTALL PLUGIN only once, not every time the server starts. Plugin loading at startup does not occur if the server is started with the --skip-grant-tables option. A plugin library can contain multiple plugins. For each of them to be installed, use a separate INSTALL PLUGIN statement. Each statement names a different plugin, but all of them specify the same library name. URL: http://dev.mysql.com/doc/refman/5.5/en/install-plugin.html :http://dev.mysql.com/doc/refman/5.5/en/install-plugin.htmlDECLARE CURSORSyntax: DECLARE cursor_name CURSOR FOR select_statement This statement declares a cursor and associates it with a SELECT statement that retrieves the rows to be traversed by the cursor. To fetch the rows later, use a FETCH statement. The number of columns retrieved by the SELECT statement must match the number of output variables specified in the FETCH statement. The SELECT statement cannot have an INTO clause. Cursor declarations must appear before handler declarations and after variable and condition declarations. A stored program may contain multiple cursor declarations, but each cursor declared in a given block must have a unique name. For an example, see http://dev.mysql.com/doc/refman/5.5/en/cursors.html. For information available through SHOW statements, it is possible in many cases to obtain equivalent information by using a cursor with an INFORMATION_SCHEMA table. URL: http://dev.mysql.com/doc/refman/5.5/en/declare-cursor.html :http://dev.mysql.com/doc/refman/5.5/en/declare-cursor.html  LOAD DATASyntax: LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name' [REPLACE | IGNORE] INTO TABLE tbl_name [CHARACTER SET charset_name] [{FIELDS | COLUMNS} [TERMINATED BY 'string'] [[OPTIONALLY] ENCLOSED BY 'char'] [ESCAPED BY 'char'] ] [LINES [STARTING BY 'string'] [TERMINATED BY 'string'] ] [IGNORE number {LINES | ROWS}] [(col_name_or_user_var,...)] [SET col_name = expr,...] The LOAD DATA INFILE statement reads rows from a text file into a table at a very high speed. The file name must be given as a literal string. LOAD DATA INFILE is the complement of SELECT ... INTO OUTFILE. (See http://dev.mysql.com/doc/refman/5.5/en/select-into.html.) To write data from a table to a file, use SELECT ... INTO OUTFILE. To read the file back into a table, use LOAD DATA INFILE. The syntax of the FIELDS and LINES clauses is the same for both statements. Both clauses are optional, but FIELDS must precede LINES if both are specified. For more information about the efficiency of INSERT versus LOAD DATA INFILE and speeding up LOAD DATA INFILE, see http://dev.mysql.com/doc/refman/5.5/en/insert-speed.html. The character set indicated by the character_set_database system variable is used to interpret the information in the file. SET NAMES and the setting of character_set_client do not affect interpretation of input. If the contents of the input file use a character set that differs from the default, it is usually preferable to specify the character set of the file by using the CHARACTER SET clause. A character set of binary specifies "no conversion." LOAD DATA INFILE interprets all fields in the file as having the same character set, regardless of the data types of the columns into which field values are loaded. For proper interpretation of file contents, you must ensure that it was written with the correct character set. For example, if you write a data file with mysqldump -T or by issuing a SELECT ... INTO OUTFILE statement in mysql, be sure to use a --default-character-set option with mysqldump or mysql so that output is written in the character set to be used when the file is loaded with LOAD DATA INFILE. *Note*: It is not possible to load data files that use the ucs2, utf16, or utf32 character set. The character_set_filesystem system variable controls the interpretation of the file name. You can also load data files by using the mysqlimport utility; it operates by sending a LOAD DATA INFILE statement to the server. The --local option causes mysqlimport to read data files from the client host. You can specify the --compress option to get better performance over slow networks if the client and server support the compressed protocol. See http://dev.mysql.com/doc/refman/5.5/en/mysqlimport.html. If you use LOW_PRIORITY, execution of the LOAD DATA statement is delayed until no other clients are reading from the table. This affects only storage engines that use only table-level locking (such as MyISAM, MEMORY, and MERGE). If you specify CONCURRENT with a MyISAM table that satisfies the condition for concurrent inserts (that is, it contains no free blocks in the middle), other threads can retrieve data from the table while LOAD DATA is executing. Using this option affects the performance of LOAD DATA a bit, even if no other thread is using the table at the same time. Prior to MySQL 5.5.1, CONCURRENT was not replicated when using statement-based replication (see Bug #34628). However, it is replicated when using row-based replication, regardless of the version. See http://dev.mysql.com/doc/refman/5.5/en/replication-features-load-data.h tml, for more information. The LOCAL keyword, if specified, is interpreted with respect to the client end of the connection: o If LOCAL is specified, the file is read by the client program on the client host and sent to the server. The file can be given as a full path name to specify its exact location. If given as a relative path name, the name is interpreted relative to the directory in which the client program was started. When using LOCAL with LOAD DATA, a copy of the file is created in the server's temporary directory. This is not the directory determined by the value of tmpdir or slave_load_tmpdir, but rather the operating system's temporary directory, and is not configurable in the MySQL Server. (Typically the system temporary directory is /tmp on Linux systems and C:\WINDOWS\TEMP on Windows.) Lack of sufficient space for the copy in this directory can cause the LOAD DATA LOCAL statement to fail. o If LOCAL is not specified, the file must be located on the server host and is read directly by the server. The server uses the following rules to locate the file: o If the file name is an absolute path name, the server uses it as given. o If the file name is a relative path name with one or more leading components, the server searches for the file relative to the server's data directory. o If a file name with no leading components is given, the server looks for the file in the database directory of the default database. Note that, in the non-LOCAL case, these rules mean that a file named as ./myfile.txt is read from the server's data directory, whereas the file named as myfile.txt is read from the database directory of the default database. For example, if db1 is the default database, the following LOAD DATA statement reads the file data.txt from the database directory for db1, even though the statement explicitly loads the file into a table in the db2 database: LOAD DATA INFILE 'data.txt' INTO TABLE db2.my_table; Windows path names are specified using forward slashes rather than backslashes. If you do use backslashes, you must double them. For security reasons, when reading text files located on the server, the files must either reside in the database directory or be readable by all. Also, to use LOAD DATA INFILE on server files, you must have the FILE privilege. See http://dev.mysql.com/doc/refman/5.5/en/privileges-provided.html. For non-LOCAL load operations, if the secure_file_priv system variable is set to a nonempty directory name, the file to be loaded must be located in that directory. URL: http://dev.mysql.com/doc/refman/5.5/en/load-data.html 5http://dev.mysql.com/doc/refman/5.5/en/load-data.htmlRMULTILINESTRINGMultiLineString(ls1,ls2,...) Constructs a MultiLineString value using LineString or WKB LineString arguments. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-mysql-specific-functions LOCALTIMESyntax: LOCALTIME, LOCALTIME() LOCALTIME and LOCALTIME() are synonyms for NOW(). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlSHOW RELAYLOG EVENTSJSyntax: SHOW RELAYLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count] Shows the events in the relay log of a replication slave. If you do not specify 'log_name', the first relay log is displayed. This statement has no effect on the master. URL: http://dev.mysql.com/doc/refman/5.5/en/show-relaylog-events.html @http://dev.mysql.com/doc/refman/5.5/en/show-relaylog-events.htmlMMPOINTFROMTEXTMPointFromText(wkt[,srid]), MultiPointFromText(wkt[,srid]) Constructs a MULTIPOINT value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkt-functionsBLOBBLOB[(M)] A BLOB column with a maximum length of 65,535 (216 - 1) bytes. Each BLOB value is stored using a 2-byte length prefix that indicates the number of bytes in the value. An optional length M can be given for this type. If this is done, MySQL creates the column as the smallest BLOB type large enough to hold values M bytes long. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlSHA1 Syntax: SHA1(str), SHA(str) Calculates an SHA-1 160-bit checksum for the string, as described in RFC 3174 (Secure Hash Algorithm). The value is returned as a string of 40 hex digits, or NULL if the argument was NULL. One of the possible uses for this function is as a hash key. See the notes at the beginning of this section about storing hash values efficiently. You can also use SHA1() as a cryptographic function for storing passwords. SHA() is synonymous with SHA1(). As of MySQL 5.5.3, the return value is a nonbinary string in the connection character set. Before 5.5.3, the return value is a binary string; see the notes at the beginning of this section about using the value as a nonbinary string. URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html Qmysql> SELECT SHA1('abc'); -> 'a9993e364706816aba3e25717850c26c9cd0d89d' @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlSUBSTR%Syntax: SUBSTR(str,pos), SUBSTR(str FROM pos), SUBSTR(str,pos,len), SUBSTR(str FROM pos FOR len) SUBSTR() is a synonym for SUBSTRING(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html]PASSWORD -Syntax: PASSWORD(str) Calculates and returns a hashed password string from the plaintext password str and returns a nonbinary string in the connection character set (a binary string before MySQL 5.5.3), or NULL if the argument is NULL. This function is the SQL interface to the algorithm used by the server to encrypt MySQL passwords for storage in the mysql.user grant table. The password hashing method used by PASSWORD() depends on the value of the old_passwords system variable: URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html mysql> SET old_passwords = 0; mysql> SELECT PASSWORD('mypass'); +-------------------------------------------+ | PASSWORD('mypass') | +-------------------------------------------+ | *6C8989366EAF75BB670AD8EA7A7FC1176A95CEF4 | +-------------------------------------------+ mysql> SET old_passwords = 1; mysql> SELECT PASSWORD('mypass'); +--------------------+ | PASSWORD('mypass') | +--------------------+ | 6f8c114b58f2ce9e | +--------------------+ @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html/CHAR[NATIONAL] CHAR[(M)] [CHARACTER SET charset_name] [COLLATE collation_name] A fixed-length string that is always right-padded with spaces to the specified length when stored. M represents the column length in characters. The range of M is 0 to 255. If M is omitted, the length is 1. *Note*: Trailing spaces are removed when CHAR values are retrieved unless the PAD_CHAR_TO_FULL_LENGTH SQL mode is enabled. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlUTC_DATESyntax: UTC_DATE, UTC_DATE() Returns the current UTC date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html Lmysql> SELECT UTC_DATE(), UTC_DATE() + 0; -> '2003-08-14', 20030814 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html DIMENSION$CDimension(g) Returns the inherent dimension of the geometry value g. The result can be -1, 0, 1, or 2. The meaning of these values is given in http://dev.mysql.com/doc/refman/5.5/en/gis-class-geometry.html. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions =mysql> SELECT Dimension(GeomFromText('LineString(1 1,2 2)')); +------------------------------------------------+ | Dimension(GeomFromText('LineString(1 1,2 2)')) | +------------------------------------------------+ | 1 | +------------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functionsCOUNT DISTINCTSyntax: COUNT(DISTINCT expr,[expr...]) Returns a count of the number of rows with different non-NULL expr values. COUNT(DISTINCT) returns 0 if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.html 4mysql> SELECT COUNT(DISTINCT results) FROM student; >http://dev.mysql.com/doc/refman/5.5/en/group-by-functions.htmlBITBIT[(M)] A bit-field type. M indicates the number of bits per value, from 1 to 64. The default is 1 if M is omitted. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlEQUALSEquals(g1,g2) Returns 1 or 0 to indicate whether g1 is spatially equal to g2. URL: http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries http://dev.mysql.com/doc/refman/5.5/en/functions-for-testing-spatial-relations-between-geometric-objects.html#functions-that-test-spatial-relationships-between-geometries SHOW CREATE VIEWSyntax: SHOW CREATE VIEW view_name This statement shows a CREATE VIEW statement that creates the given view. URL: http://dev.mysql.com/doc/refman/5.5/en/show-create-view.html <http://dev.mysql.com/doc/refman/5.5/en/show-create-view.htmlbINTERVALVSyntax: INTERVAL(N,N1,N2,N3,...) Returns 0 if N < N1, 1 if N < N2 and so on or -1 if N is NULL. All arguments are treated as integers. It is required that N1 < N2 < N3 < ... < Nn for this function to work correctly. This is because a binary search is used (very fast). URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT INTERVAL(23, 1, 15, 17, 30, 44, 200); -> 3 mysql> SELECT INTERVAL(10, 1, 10, 100, 1000); -> 2 mysql> SELECT INTERVAL(22, 23, 30, 44, 200); -> 0 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html  FROM_DAYSSyntax: FROM_DAYS(N) Given a day number N, returns a DATE value. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 9mysql> SELECT FROM_DAYS(730669); -> '2007-07-03' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlALTER PROCEDURE'Syntax: ALTER PROCEDURE proc_name [characteristic ...] characteristic: COMMENT 'string' | LANGUAGE SQL | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } This statement can be used to change the characteristics of a stored procedure. More than one change may be specified in an ALTER PROCEDURE statement. However, you cannot change the parameters or body of a stored procedure using this statement; to make such changes, you must drop and re-create the procedure using DROP PROCEDURE and CREATE PROCEDURE. You must have the ALTER ROUTINE privilege for the procedure. By default, that privilege is granted automatically to the procedure creator. This behavior can be changed by disabling the automatic_sp_privileges system variable. See http://dev.mysql.com/doc/refman/5.5/en/stored-routines-privileges.html. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-procedure.html ;http://dev.mysql.com/doc/refman/5.5/en/alter-procedure.html% BIT_COUNTSyntax: BIT_COUNT(N) Returns the number of bits that are set in the argument N. URL: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html Cmysql> SELECT BIT_COUNT(29), BIT_COUNT(b'101010'); -> 4, 3 9http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html OCTET_LENGTH%Syntax: OCTET_LENGTH(str) OCTET_LENGTH() is a synonym for LENGTH(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html UTC_TIMESTAMP(Syntax: UTC_TIMESTAMP, UTC_TIMESTAMP() Returns the current UTC date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html lmysql> SELECT UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0; -> '2003-08-14 18:08:04', 20030814180804.000000 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlP AES_ENCRYPT Syntax: AES_ENCRYPT(str,key_str) AES_ENCRYPT() and AES_DECRYPT() enable encryption and decryption of data using the official AES (Advanced Encryption Standard) algorithm, previously known as "Rijndael." Encoding with a 128-bit key length is used, but you can extend it up to 256 bits by modifying the source. We chose 128 bits because it is much faster and it is secure enough for most purposes. AES_ENCRYPT() encrypts a string and returns a binary string. AES_DECRYPT() decrypts the encrypted string and returns the original string. The input arguments may be any length. If either argument is NULL, the result of this function is also NULL. Because AES is a block-level algorithm, padding is used to encode uneven length strings and so the result string length may be calculated using this formula: 16 * (trunc(string_length / 16) + 1) If AES_DECRYPT() detects invalid data or incorrect padding, it returns NULL. However, it is possible for AES_DECRYPT() to return a non-NULL value (possibly garbage) if the input data or the key is invalid. You can use the AES functions to store data in an encrypted form by modifying your queries: URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html 9INSERT INTO t VALUES (1,AES_ENCRYPT('text','password')); @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html+]Syntax: + Addition: URL: http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.html mysql> SELECT 3+5; -> 8 @http://dev.mysql.com/doc/refman/5.5/en/arithmetic-functions.htmlG INET_NTOASyntax: INET_NTOA(expr) Given a numeric IPv4 network address in network byte order, returns the dotted-quad representation of the address as a string. INET_NTOA() returns NULL if it does not understand its argument. As of MySQL 5.5.3, the return value is a nonbinary string in the connection character set. Before 5.5.3, the return value is a binary string. URL: http://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.html :mysql> SELECT INET_NTOA(167773449); -> '10.0.5.9' Chttp://dev.mysql.com/doc/refman/5.5/en/miscellaneous-functions.htmlACOSSyntax: ACOS(X) Returns the arc cosine of X, that is, the value whose cosine is X. Returns NULL if X is not in the range -1 to 1. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html mysql> SELECT ACOS(1); -> 0 mysql> SELECT ACOS(1.0001); -> NULL mysql> SELECT ACOS(0); -> 1.5707963267949 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html ISOLATIONSyntax: SET [GLOBAL | SESSION] TRANSACTION ISOLATION LEVEL { REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED | SERIALIZABLE } This statement sets the transaction isolation level, used for operations on InnoDB tables. Scope of the Isolation Level You can set the isolation level globally, for the current session, or for the next transaction: o With the GLOBAL keyword, the statement sets the default transaction level globally for all subsequent sessions. Existing sessions are unaffected. o With the SESSION keyword, the statement sets the default transaction level for all subsequent transactions performed within the current session. o Without any SESSION or GLOBAL keyword, the statement sets the isolation level for the next (not started) transaction performed within the current session. A change to the global default isolation level requires the SUPER privilege. Any session is free to change its session isolation level (even in the middle of a transaction), or the isolation level for its next transaction. SET TRANSACTION ISOLATION LEVEL without GLOBAL or SESSION is not permitted while there is an active transaction: mysql> START TRANSACTION; Query OK, 0 rows affected (0.02 sec) mysql> SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; ERROR 1568 (25001): Transaction isolation level can't be changed while a transaction is in progress To set the global default isolation level at server startup, use the --transaction-isolation=level option to mysqld on the command line or in an option file. Values of level for this option use dashes rather than spaces, so the permissible values are READ-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ, or SERIALIZABLE. For example, to set the default isolation level to REPEATABLE READ, use these lines in the [mysqld] section of an option file: [mysqld] transaction-isolation = REPEATABLE-READ It is possible to check or set the global and session transaction isolation levels at runtime by using the tx_isolation system variable: SELECT @@GLOBAL.tx_isolation, @@tx_isolation; SET GLOBAL tx_isolation='REPEATABLE-READ'; SET SESSION tx_isolation='SERIALIZABLE'; Details and Usage of Isolation Levels InnoDB supports each of the transaction isolation levels described here using different locking strategies. You can enforce a high degree of consistency with the default REPEATABLE READ level, for operations on crucial data where ACID compliance is important. Or you can relax the consistency rules with READ COMMITTED or even READ UNCOMMITTED, in situations such as bulk reporting where precise consistency and repeatable results are less important than minimizing the amount of overhead for locking. SERIALIZABLE enforces even stricter rules than REPEATABLE READ, and is used mainly in specialized situations, such as with XA transactions and for troubleshooting issues with concurrency and deadlocks. For full information about how these isolation levels work with InnoDB transactions, see http://dev.mysql.com/doc/refman/5.5/en/innodb-transaction-model.html. In particular, for additional information about InnoDB record-level locks and how it uses them to execute various types of statements, see http://dev.mysql.com/doc/refman/5.5/en/innodb-record-level-locks.html and http://dev.mysql.com/doc/refman/5.5/en/innodb-locks-set.html. The following list describes how MySQL supports the different transaction levels. The list goes from the most commonly used level to the least used. o REPEATABLE READ This is the default isolation level for InnoDB. For consistent reads, there is an important difference from the READ COMMITTED isolation level: All consistent reads within the same transaction read the snapshot established by the first read. This convention means that if you issue several plain (nonlocking) SELECT statements within the same transaction, these SELECT statements are consistent also with respect to each other. See http://dev.mysql.com/doc/refman/5.5/en/innodb-consistent-read.html. For locking reads (SELECT with FOR UPDATE or LOCK IN SHARE MODE), UPDATE, and DELETE statements, locking depends on whether the statement uses a unique index with a unique search condition, or a range-type search condition. For a unique index with a unique search condition, InnoDB locks only the index record found, not the gap before it. For other search conditions, InnoDB locks the index range scanned, using gap locks or next-key (gap plus index-record) locks to block insertions by other sessions into the gaps covered by the range. o READ COMMITTED A somewhat Oracle-like isolation level with respect to consistent (nonlocking) reads: Each consistent read, even within the same transaction, sets and reads its own fresh snapshot. See http://dev.mysql.com/doc/refman/5.5/en/innodb-consistent-read.html. For locking reads (SELECT with FOR UPDATE or LOCK IN SHARE MODE), InnoDB locks only index records, not the gaps before them, and thus permits the free insertion of new records next to locked records. For UPDATE and DELETE statements, locking depends on whether the statement uses a unique index with a unique search condition (such as WHERE id = 100), or a range-type search condition (such as WHERE id > 100). For a unique index with a unique search condition, InnoDB locks only the index record found, not the gap before it. For range-type searches, InnoDB locks the index range scanned, using gap locks or next-key (gap plus index-record) locks to block insertions by other sessions into the gaps covered by the range. This is necessary because "phantom rows" must be blocked for MySQL replication and recovery to work. *Note*: In MySQL 5.5, if the READ COMMITTED isolation level is used or the innodb_locks_unsafe_for_binlog system variable is enabled, there is no InnoDB gap locking except for foreign-key constraint checking and duplicate-key checking. Also, record locks for nonmatching rows are released after MySQL has evaluated the WHERE condition. If you use READ COMMITTED or enable innodb_locks_unsafe_for_binlog, you must use row-based binary logging. o READ UNCOMMITTED SELECT statements are performed in a nonlocking fashion, but a possible earlier version of a row might be used. Thus, using this isolation level, such reads are not consistent. This is also called a "dirty read." Otherwise, this isolation level works like READ COMMITTED. o SERIALIZABLE This level is like REPEATABLE READ, but InnoDB implicitly converts all plain SELECT statements to SELECT ... LOCK IN SHARE MODE if autocommit is disabled. If autocommit is enabled, the SELECT is its own transaction. It therefore is known to be read only and can be serialized if performed as a consistent (nonlocking) read and need not block for other transactions. (To force a plain SELECT to block if other transactions have modified the selected rows, disable autocommit.) URL: http://dev.mysql.com/doc/refman/5.5/en/set-transaction.html ;http://dev.mysql.com/doc/refman/5.5/en/set-transaction.html?CEILINGSyntax: CEILING(X) Returns the smallest integer value not less than X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Vmysql> SELECT CEILING(1.23); -> 2 mysql> SELECT CEILING(-1.23); -> -1 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlFSINSyntax: SIN(X) Returns the sine of X, where X is given in radians. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html emysql> SELECT SIN(PI()); -> 1.2246063538224e-16 mysql> SELECT ROUND(SIN(PI())); -> 0 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlv DAYOFWEEKSyntax: DAYOFWEEK(date) Returns the weekday index for date (1 = Sunday, 2 = Monday, ..., 7 = Saturday). These index values correspond to the ODBC standard. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 4mysql> SELECT DAYOFWEEK('2007-02-03'); -> 7 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlSHOW PROCESSLIST5Syntax: SHOW [FULL] PROCESSLIST SHOW PROCESSLIST shows you which threads are running. You can also get this information from the INFORMATION_SCHEMA PROCESSLIST table or the mysqladmin processlist command. If you have the PROCESS privilege, you can see all threads. Otherwise, you can see only your own threads (that is, threads associated with the MySQL account that you are using). If you do not use the FULL keyword, only the first 100 characters of each statement are shown in the Info field. URL: http://dev.mysql.com/doc/refman/5.5/en/show-processlist.html <http://dev.mysql.com/doc/refman/5.5/en/show-processlist.htmlF LINEFROMWKB LineFromWKB(wkb[,srid]), LineStringFromWKB(wkb[,srid]) Constructs a LINESTRING value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions GEOMETRYTYPE$0GeometryType(g) Returns as a binary string the name of the geometry type of which the geometry instance g is a member. The name corresponds to one of the instantiable Geometry subclasses. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions mysql> SELECT GeometryType(GeomFromText('POINT(1 1)')); +------------------------------------------+ | GeometryType(GeomFromText('POINT(1 1)')) | +------------------------------------------+ | POINT | +------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#general-geometry-property-functions1G CREATE VIEW'0Syntax: CREATE [OR REPLACE] [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}] [DEFINER = { user | CURRENT_USER }] [SQL SECURITY { DEFINER | INVOKER }] VIEW view_name [(column_list)] AS select_statement [WITH [CASCADED | LOCAL] CHECK OPTION] The CREATE VIEW statement creates a new view, or replaces an existing one if the OR REPLACE clause is given. If the view does not exist, CREATE OR REPLACE VIEW is the same as CREATE VIEW. If the view does exist, CREATE OR REPLACE VIEW is the same as ALTER VIEW. The select_statement is a SELECT statement that provides the definition of the view. (When you select from the view, you select in effect using the SELECT statement.) select_statement can select from base tables or other views. The view definition is "frozen" at creation time, so changes to the underlying tables afterward do not affect the view definition. For example, if a view is defined as SELECT * on a table, new columns added to the table later do not become part of the view. The ALGORITHM clause affects how MySQL processes the view. The DEFINER and SQL SECURITY clauses specify the security context to be used when checking access privileges at view invocation time. The WITH CHECK OPTION clause can be given to constrain inserts or updates to rows in tables referenced by the view. These clauses are described later in this section. The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. For columns used elsewhere in the SELECT statement you must have the SELECT privilege. If the OR REPLACE clause is present, you must also have the DROP privilege for the view. CREATE VIEW might also require the SUPER privilege, depending on the DEFINER value, as described later in this section. When a view is referenced, privilege checking occurs as described later in this section. A view belongs to a database. By default, a new view is created in the default database. To create the view explicitly in a given database, specify the name as db_name.view_name when you create it: mysql> CREATE VIEW test.v AS SELECT * FROM t; Within a database, base tables and views share the same namespace, so a base table and a view cannot have the same name. Columns retrieved by the SELECT statement can be simple references to table columns. They can also be expressions that use functions, constant values, operators, and so forth. Views must have unique column names with no duplicates, just like base tables. By default, the names of the columns retrieved by the SELECT statement are used for the view column names. To define explicit names for the view columns, the optional column_list clause can be given as a list of comma-separated identifiers. The number of names in column_list must be the same as the number of columns retrieved by the SELECT statement. Unqualified table or view names in the SELECT statement are interpreted with respect to the default database. A view can refer to tables or views in other databases by qualifying the table or view name with the proper database name. A view can be created from many kinds of SELECT statements. It can refer to base tables or other views. It can use joins, UNION, and subqueries. The SELECT need not even refer to any tables. The following example defines a view that selects two columns from another table, as well as an expression calculated from those columns: mysql> CREATE TABLE t (qty INT, price INT); mysql> INSERT INTO t VALUES(3, 50); mysql> CREATE VIEW v AS SELECT qty, price, qty*price AS value FROM t; mysql> SELECT * FROM v; +------+-------+-------+ | qty | price | value | +------+-------+-------+ | 3 | 50 | 150 | +------+-------+-------+ A view definition is subject to the following restrictions: o The SELECT statement cannot contain a subquery in the FROM clause. o The SELECT statement cannot refer to system or user variables. o Within a stored program, the definition cannot refer to program parameters or local variables. o The SELECT statement cannot refer to prepared statement parameters. o Any table or view referred to in the definition must exist. However, after a view has been created, it is possible to drop a table or view that the definition refers to. In this case, use of the view results in an error. To check a view definition for problems of this kind, use the CHECK TABLE statement. o The definition cannot refer to a TEMPORARY table, and you cannot create a TEMPORARY view. o Any tables named in the view definition must exist at definition time. o You cannot associate a trigger with a view. o Aliases for column names in the SELECT statement are checked against the maximum column length of 64 characters (not the maximum alias length of 256 characters). ORDER BY is permitted in a view definition, but it is ignored if you select from a view using a statement that has its own ORDER BY. For other options or clauses in the definition, they are added to the options or clauses of the statement that references the view, but the effect is undefined. For example, if a view definition includes a LIMIT clause, and you select from the view using a statement that has its own LIMIT clause, it is undefined which limit applies. This same principle applies to options such as ALL, DISTINCT, or SQL_SMALL_RESULT that follow the SELECT keyword, and to clauses such as INTO, FOR UPDATE, LOCK IN SHARE MODE, and PROCEDURE. If you create a view and then change the query processing environment by changing system variables, that may affect the results that you get from the view: mysql> CREATE VIEW v (mycol) AS SELECT 'abc'; Query OK, 0 rows affected (0.01 sec) mysql> SET sql_mode = ''; Query OK, 0 rows affected (0.00 sec) mysql> SELECT "mycol" FROM v; +-------+ | mycol | +-------+ | mycol | +-------+ 1 row in set (0.01 sec) mysql> SET sql_mode = 'ANSI_QUOTES'; Query OK, 0 rows affected (0.00 sec) mysql> SELECT "mycol" FROM v; +-------+ | mycol | +-------+ | abc | +-------+ 1 row in set (0.00 sec) The DEFINER and SQL SECURITY clauses determine which MySQL account to use when checking access privileges for the view when a statement is executed that references the view. The valid SQL SECURITY characteristic values are DEFINER and INVOKER. These indicate that the required privileges must be held by the user who defined or invoked the view, respectively. The default SQL SECURITY value is DEFINER. If a user value is given for the DEFINER clause, it should be a MySQL account specified as 'user_name'@'host_name' (the same format used in the GRANT statement), CURRENT_USER, or CURRENT_USER(). The default DEFINER value is the user who executes the CREATE VIEW statement. This is the same as specifying DEFINER = CURRENT_USER explicitly. If you specify the DEFINER clause, these rules determine the valid DEFINER user values: o If you do not have the SUPER privilege, the only valid user value is your own account, either specified literally or by using CURRENT_USER. You cannot set the definer to some other account. o If you have the SUPER privilege, you can specify any syntactically valid account name. If the account does not actually exist, a warning is generated. o Although it is possible to create a view with a nonexistent DEFINER account, an error occurs when the view is referenced if the SQL SECURITY value is DEFINER but the definer account does not exist. For more information about view security, see http://dev.mysql.com/doc/refman/5.5/en/stored-programs-security.html. Within a view definition, CURRENT_USER returns the view's DEFINER value by default. For views defined with the SQL SECURITY INVOKER characteristic, CURRENT_USER returns the account for the view's invoker. For information about user auditing within views, see http://dev.mysql.com/doc/refman/5.5/en/account-activity-auditing.html. Within a stored routine that is defined with the SQL SECURITY DEFINER characteristic, CURRENT_USER returns the routine's DEFINER value. This also affects a view defined within such a routine, if the view definition contains a DEFINER value of CURRENT_USER. View privileges are checked like this: o At view definition time, the view creator must have the privileges needed to use the top-level objects accessed by the view. For example, if the view definition refers to table columns, the creator must have some privilege for each column in the select list of the definition, and the SELECT privilege for each column used elsewhere in the definition. If the definition refers to a stored function, only the privileges needed to invoke the function can be checked. The privileges required at function invocation time can be checked only as it executes: For different invocations, different execution paths within the function might be taken. o The user who references a view must have appropriate privileges to access it (SELECT to select from it, INSERT to insert into it, and so forth.) o When a view has been referenced, privileges for objects accessed by the view are checked against the privileges held by the view DEFINER account or invoker, depending on whether the SQL SECURITY characteristic is DEFINER or INVOKER, respectively. o If reference to a view causes execution of a stored function, privilege checking for statements executed within the function depend on whether the function SQL SECURITY characteristic is DEFINER or INVOKER. If the security characteristic is DEFINER, the function runs with the privileges of the DEFINER account. If the characteristic is INVOKER, the function runs with the privileges determined by the view's SQL SECURITY characteristic. Example: A view might depend on a stored function, and that function might invoke other stored routines. For example, the following view invokes a stored function f(): CREATE VIEW v AS SELECT * FROM t WHERE t.id = f(t.name); Suppose that f() contains a statement such as this: IF name IS NULL then CALL p1(); ELSE CALL p2(); END IF; The privileges required for executing statements within f() need to be checked when f() executes. This might mean that privileges are needed for p1() or p2(), depending on the execution path within f(). Those privileges must be checked at runtime, and the user who must possess the privileges is determined by the SQL SECURITY values of the view v and the function f(). The DEFINER and SQL SECURITY clauses for views are extensions to standard SQL. In standard SQL, views are handled using the rules for SQL SECURITY DEFINER. The standard says that the definer of the view, which is the same as the owner of the view's schema, gets applicable privileges on the view (for example, SELECT) and may grant them. MySQL has no concept of a schema "owner", so MySQL adds a clause to identify the definer. The DEFINER clause is an extension where the intent is to have what the standard has; that is, a permanent record of who defined the view. This is why the default DEFINER value is the account of the view creator. The optional ALGORITHM clause is a MySQL extension to standard SQL. It affects how MySQL processes the view. ALGORITHM takes three values: MERGE, TEMPTABLE, or UNDEFINED. The default algorithm is UNDEFINED if no ALGORITHM clause is present. For more information, see http://dev.mysql.com/doc/refman/5.5/en/view-algorithms.html. Some views are updatable. That is, you can use them in statements such as UPDATE, DELETE, or INSERT to update the contents of the underlying table. For a view to be updatable, there must be a one-to-one relationship between the rows in the view and the rows in the underlying table. There are also certain other constructs that make a view nonupdatable. The WITH CHECK OPTION clause can be given for an updatable view to prevent inserts or updates to rows except those for which the WHERE clause in the select_statement is true. In a WITH CHECK OPTION clause for an updatable view, the LOCAL and CASCADED keywords determine the scope of check testing when the view is defined in terms of another view. The LOCAL keyword restricts the CHECK OPTION only to the view being defined. CASCADED causes the checks for underlying views to be evaluated as well. When neither keyword is given, the default is CASCADED. For more information about updatable views and the WITH CHECK OPTION clause, see http://dev.mysql.com/doc/refman/5.5/en/view-updatability.html. URL: http://dev.mysql.com/doc/refman/5.5/en/create-view.html 7http://dev.mysql.com/doc/refman/5.5/en/create-view.htmlTRIM%oSyntax: TRIM([{BOTH | LEADING | TRAILING} [remstr] FROM] str), TRIM([remstr FROM] str) Returns the string str with all remstr prefixes or suffixes removed. If none of the specifiers BOTH, LEADING, or TRAILING is given, BOTH is assumed. remstr is optional and, if not specified, spaces are removed. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT TRIM(' bar '); -> 'bar' mysql> SELECT TRIM(LEADING 'x' FROM 'xxxbarxxx'); -> 'barxxx' mysql> SELECT TRIM(BOTH 'x' FROM 'xxxbarxxx'); -> 'bar' mysql> SELECT TRIM(TRAILING 'xyz' FROM 'barxxyz'); -> 'barx' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlVISSyntax: IS boolean_value Tests a value against a boolean value, where boolean_value can be TRUE, FALSE, or UNKNOWN. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html Imysql> SELECT 1 IS TRUE, 0 IS FALSE, NULL IS UNKNOWN; -> 1, 1, 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html GET_FORMATSyntax: GET_FORMAT({DATE|TIME|DATETIME}, {'EUR'|'USA'|'JIS'|'ISO'|'INTERNAL'}) Returns a format string. This function is useful in combination with the DATE_FORMAT() and the STR_TO_DATE() functions. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT DATE_FORMAT('2003-10-03',GET_FORMAT(DATE,'EUR')); -> '03.10.2003' mysql> SELECT STR_TO_DATE('10.31.2003',GET_FORMAT(DATE,'USA')); -> '2003-10-31' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlMTINYBLOBTINYBLOB A BLOB column with a maximum length of 255 (28 - 1) bytes. Each TINYBLOB value is stored using a 1-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html SIGNAL Syntax: SIGNAL condition_value [SET signal_information_item [, signal_information_item] ...] condition_value: SQLSTATE [VALUE] sqlstate_value | condition_name signal_information_item: condition_information_item_name = simple_value_specification condition_information_item_name: CLASS_ORIGIN | SUBCLASS_ORIGIN | MESSAGE_TEXT | MYSQL_ERRNO | CONSTRAINT_CATALOG | CONSTRAINT_SCHEMA | CONSTRAINT_NAME | CATALOG_NAME | SCHEMA_NAME | TABLE_NAME | COLUMN_NAME | CURSOR_NAME condition_name, simple_value_specification: (see following discussion) SIGNAL is the way to "return" an error. SIGNAL provides error information to a handler, to an outer portion of the application, or to the client. Also, it provides control over the error's characteristics (error number, SQLSTATE value, message). Without SIGNAL, it is necessary to resort to workarounds such as deliberately referring to a nonexistent table to cause a routine to return an error. No special privileges are required to execute the SIGNAL statement. The condition_value in a SIGNAL statement indicates the error value to be returned. It can be an SQLSTATE value (a 5-character string literal) or a condition_name that refers to a named condition previously defined with DECLARE ... CONDITION (see [HELP DECLARE CONDITION]). An SQLSTATE value can indicate errors, warnings, or "not found." The first two characters of the value indicate its error class, as discussed in http://dev.mysql.com/doc/refman/5.5/en/signal.html#signal-condition-inf ormation-items. Some signal values cause statement termination; see http://dev.mysql.com/doc/refman/5.5/en/signal.html#signal-effects. The SQLSTATE value for a SIGNAL statement should not start with '00' because such values indicate success and are not valid for signaling an error. This is true whether the SQLSTATE value is specified directly in the SIGNAL statement or in a named condition referred to in the statement. If the value is invalid, a Bad SQLSTATE error occurs. To signal a generic SQLSTATE value, use '45000', which means "unhandled user-defined exception." The SIGNAL statement optionally includes a SET clause that contains multiple signal items, in a comma-separated list of condition_information_item_name = simple_value_specification assignments. Each condition_information_item_name may be specified only once in the SET clause. Otherwise, a Duplicate condition information item error occurs. Valid simple_value_specification designators can be specified using stored procedure or function parameters, stored program local variables declared with DECLARE, user-defined variables, system variables, or literals. A character literal may include a _charset introducer. For information about permissible condition_information_item_name values, see http://dev.mysql.com/doc/refman/5.5/en/signal.html#signal-condition-inf ormation-items. URL: http://dev.mysql.com/doc/refman/5.5/en/signal.html CREATE PROCEDURE p (pval INT) BEGIN DECLARE specialty CONDITION FOR SQLSTATE '45000'; IF pval = 0 THEN SIGNAL SQLSTATE '01000'; ELSEIF pval = 1 THEN SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'An error occurred'; ELSEIF pval = 2 THEN SIGNAL specialty SET MESSAGE_TEXT = 'An error occurred'; ELSE SIGNAL SQLSTATE '01000' SET MESSAGE_TEXT = 'A warning occurred', MYSQL_ERRNO = 1000; SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'An error occurred', MYSQL_ERRNO = 1001; END IF; END; 2http://dev.mysql.com/doc/refman/5.5/en/signal.htmlo SAVEPOINT%Syntax: SAVEPOINT identifier ROLLBACK [WORK] TO [SAVEPOINT] identifier RELEASE SAVEPOINT identifier InnoDB supports the SQL statements SAVEPOINT, ROLLBACK TO SAVEPOINT, RELEASE SAVEPOINT and the optional WORK keyword for ROLLBACK. URL: http://dev.mysql.com/doc/refman/5.5/en/savepoint.html 5http://dev.mysql.com/doc/refman/5.5/en/savepoint.html9USERSyntax: USER() Returns the current MySQL user name and host name as a string in the utf8 character set. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html 4mysql> SELECT USER(); -> 'davida@localhost' Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.htmlVLABELSSyntax: [begin_label:] BEGIN [statement_list] END [end_label] [begin_label:] LOOP statement_list END LOOP [end_label] [begin_label:] REPEAT statement_list UNTIL search_condition END REPEAT [end_label] [begin_label:] WHILE search_condition DO statement_list END WHILE [end_label] Labels are permitted for BEGIN ... END blocks and for the LOOP, REPEAT, and WHILE statements. Label use for those statements follows these rules: o begin_label must be followed by a colon. o begin_label can be given without end_label. If end_label is present, it must be the same as begin_label. o end_label cannot be given without begin_label. o Labels at the same nesting level must be distinct. o Labels can be up to 16 characters long. To refer to a label within the labeled construct, use an ITERATE or LEAVE statement. The following example uses those statements to continue iterating or terminate the loop: CREATE PROCEDURE doiterate(p1 INT) BEGIN label1: LOOP SET p1 = p1 + 1; IF p1 < 10 THEN ITERATE label1; END IF; LEAVE label1; END LOOP label1; END; The scope of a block label does not include the code for handlers declared within the block. For details, see [HELP DECLARE HANDLER]. URL: http://dev.mysql.com/doc/refman/5.5/en/statement-labels.html <http://dev.mysql.com/doc/refman/5.5/en/statement-labels.html  ALTER TABLE' Syntax: ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name [alter_specification [, alter_specification] ...] [partition_options] alter_specification: table_options | ADD [COLUMN] col_name column_definition [FIRST | AFTER col_name ] | ADD [COLUMN] (col_name column_definition,...) | ADD {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD FULLTEXT [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD SPATIAL [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition | ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT} | CHANGE [COLUMN] old_col_name new_col_name column_definition [FIRST|AFTER col_name] | MODIFY [COLUMN] col_name column_definition [FIRST | AFTER col_name] | DROP [COLUMN] col_name | DROP PRIMARY KEY | DROP {INDEX|KEY} index_name | DROP FOREIGN KEY fk_symbol | MAX_ROWS = rows | DISABLE KEYS | ENABLE KEYS | RENAME [TO|AS] new_tbl_name | ORDER BY col_name [, col_name] ... | CONVERT TO CHARACTER SET charset_name [COLLATE collation_name] | [DEFAULT] CHARACTER SET [=] charset_name [COLLATE [=] collation_name] | DISCARD TABLESPACE | IMPORT TABLESPACE | FORCE | ADD PARTITION (partition_definition) | DROP PARTITION partition_names | TRUNCATE PARTITION {partition_names | ALL} | COALESCE PARTITION number | REORGANIZE PARTITION [partition_names INTO (partition_definitions)] | ANALYZE PARTITION {partition_names | ALL} | CHECK PARTITION {partition_names | ALL} | OPTIMIZE PARTITION {partition_names | ALL} | REBUILD PARTITION {partition_names | ALL} | REPAIR PARTITION {partition_names | ALL} | PARTITION BY partitioning_expression | REMOVE PARTITIONING index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' table_options: table_option [[,] table_option] ... (see CREATE TABLE options) partition_options: (see CREATE TABLE options) ALTER TABLE changes the structure of a table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or the table itself. You can also change characteristics such as the storage engine used for the table or the table comment. Partitioning-related clauses for ALTER TABLE can be used with partitioned tables for repartitioning, for adding, dropping, merging, and splitting partitions, and for performing partitioning maintenance. For more information, see http://dev.mysql.com/doc/refman/5.5/en/alter-table-partition-operations .html. Following the table name, specify the alterations to be made. If none are given, ALTER TABLE does nothing. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-table.html 7http://dev.mysql.com/doc/refman/5.5/en/alter-table.htmlJ MPOINTFROMWKB MPointFromWKB(wkb[,srid]), MultiPointFromWKB(wkb[,srid]) Constructs a MULTIPOINT value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions CHAR BYTEThe CHAR BYTE data type is an alias for the BINARY data type. This is a compatibility feature. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html REPAIR TABLESyntax: REPAIR [NO_WRITE_TO_BINLOG | LOCAL] TABLE tbl_name [, tbl_name] ... [QUICK] [EXTENDED] [USE_FRM] REPAIR TABLE repairs a possibly corrupted table. By default, it has the same effect as myisamchk --recover tbl_name. REPAIR TABLE works for MyISAM, ARCHIVE, and CSV tables. See http://dev.mysql.com/doc/refman/5.5/en/myisam-storage-engine.html, and http://dev.mysql.com/doc/refman/5.5/en/archive-storage-engine.html, and http://dev.mysql.com/doc/refman/5.5/en/csv-storage-engine.html This statement requires SELECT and INSERT privileges for the table. REPAIR TABLE is supported for partitioned tables. However, the USE_FRM option cannot be used with this statement on a partitioned table. You can use ALTER TABLE ... REPAIR PARTITION to repair one or more partitions; for more information, see [HELP ALTER TABLE], and http://dev.mysql.com/doc/refman/5.5/en/partitioning-maintenance.html. URL: http://dev.mysql.com/doc/refman/5.5/en/repair-table.html 8http://dev.mysql.com/doc/refman/5.5/en/repair-table.htmlMERGE'The MERGE storage engine, also known as the MRG_MyISAM engine, is a collection of identical MyISAM tables that can be used as one. "Identical" means that all tables have identical column and index information. You cannot merge MyISAM tables in which the columns are listed in a different order, do not have exactly the same columns, or have the indexes in different order. However, any or all of the MyISAM tables can be compressed with myisampack. See http://dev.mysql.com/doc/refman/5.5/en/myisampack.html. Differences in table options such as AVG_ROW_LENGTH, MAX_ROWS, or PACK_KEYS do not matter. URL: http://dev.mysql.com/doc/refman/5.5/en/merge-storage-engine.html mysql> CREATE TABLE t1 ( -> a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, -> message CHAR(20)) ENGINE=MyISAM; mysql> CREATE TABLE t2 ( -> a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, -> message CHAR(20)) ENGINE=MyISAM; mysql> INSERT INTO t1 (message) VALUES ('Testing'),('table'),('t1'); mysql> INSERT INTO t2 (message) VALUES ('Testing'),('table'),('t2'); mysql> CREATE TABLE total ( -> a INT NOT NULL AUTO_INCREMENT, -> message CHAR(20), INDEX(a)) -> ENGINE=MERGE UNION=(t1,t2) INSERT_METHOD=LAST; @http://dev.mysql.com/doc/refman/5.5/en/merge-storage-engine.html CREATE TABLE'Syntax: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name (create_definition,...) [table_options] [partition_options] Or: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [partition_options] select_statement Or: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition: col_name column_definition | [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ... | [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | {FULLTEXT|SPATIAL} [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition | CHECK (expr) column_definition: data_type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY] [COMMENT 'string'] [COLUMN_FORMAT {FIXED|DYNAMIC|DEFAULT}] [STORAGE {DISK|MEMORY|DEFAULT}] [reference_definition] data_type: BIT[(length)] | TINYINT[(length)] [UNSIGNED] [ZEROFILL] | SMALLINT[(length)] [UNSIGNED] [ZEROFILL] | MEDIUMINT[(length)] [UNSIGNED] [ZEROFILL] | INT[(length)] [UNSIGNED] [ZEROFILL] | INTEGER[(length)] [UNSIGNED] [ZEROFILL] | BIGINT[(length)] [UNSIGNED] [ZEROFILL] | REAL[(length,decimals)] [UNSIGNED] [ZEROFILL] | DOUBLE[(length,decimals)] [UNSIGNED] [ZEROFILL] | FLOAT[(length,decimals)] [UNSIGNED] [ZEROFILL] | DECIMAL[(length[,decimals])] [UNSIGNED] [ZEROFILL] | NUMERIC[(length[,decimals])] [UNSIGNED] [ZEROFILL] | DATE | TIME | TIMESTAMP | DATETIME | YEAR | CHAR[(length)] [CHARACTER SET charset_name] [COLLATE collation_name] | VARCHAR(length) [CHARACTER SET charset_name] [COLLATE collation_name] | BINARY[(length)] | VARBINARY(length) | TINYBLOB | BLOB | MEDIUMBLOB | LONGBLOB | TINYTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | TEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | MEDIUMTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | LONGTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | ENUM(value1,value2,value3,...) [CHARACTER SET charset_name] [COLLATE collation_name] | SET(value1,value2,value3,...) [CHARACTER SET charset_name] [COLLATE collation_name] | spatial_type index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' reference_definition: REFERENCES tbl_name (index_col_name,...) [MATCH FULL | MATCH PARTIAL | MATCH SIMPLE] [ON DELETE reference_option] [ON UPDATE reference_option] reference_option: RESTRICT | CASCADE | SET NULL | NO ACTION table_options: table_option [[,] table_option] ... table_option: ENGINE [=] engine_name | AUTO_INCREMENT [=] value | AVG_ROW_LENGTH [=] value | [DEFAULT] CHARACTER SET [=] charset_name | CHECKSUM [=] {0 | 1} | [DEFAULT] COLLATE [=] collation_name | COMMENT [=] 'string' | CONNECTION [=] 'connect_string' | DATA DIRECTORY [=] 'absolute path to directory' | DELAY_KEY_WRITE [=] {0 | 1} | INDEX DIRECTORY [=] 'absolute path to directory' | INSERT_METHOD [=] { NO | FIRST | LAST } | KEY_BLOCK_SIZE [=] value | MAX_ROWS [=] value | MIN_ROWS [=] value | PACK_KEYS [=] {0 | 1 | DEFAULT} | PASSWORD [=] 'string' | ROW_FORMAT [=] {DEFAULT|DYNAMIC|FIXED|COMPRESSED|REDUNDANT|COMPACT} | TABLESPACE tablespace_name [STORAGE {DISK|MEMORY|DEFAULT}] | UNION [=] (tbl_name[,tbl_name]...) partition_options: PARTITION BY { [LINEAR] HASH(expr) | [LINEAR] KEY(column_list) | RANGE{(expr) | COLUMNS(column_list)} | LIST{(expr) | COLUMNS(column_list)} } [PARTITIONS num] [SUBPARTITION BY { [LINEAR] HASH(expr) | [LINEAR] KEY(column_list) } [SUBPARTITIONS num] ] [(partition_definition [, partition_definition] ...)] partition_definition: PARTITION partition_name [VALUES {LESS THAN {(expr | value_list) | MAXVALUE} | IN (value_list)}] [[STORAGE] ENGINE [=] engine_name] [COMMENT [=] 'comment_text' ] [DATA DIRECTORY [=] 'data_dir'] [INDEX DIRECTORY [=] 'index_dir'] [MAX_ROWS [=] max_number_of_rows] [MIN_ROWS [=] min_number_of_rows] [TABLESPACE [=] tablespace_name] [NODEGROUP [=] node_group_id] [(subpartition_definition [, subpartition_definition] ...)] subpartition_definition: SUBPARTITION logical_name [[STORAGE] ENGINE [=] engine_name] [COMMENT [=] 'comment_text' ] [DATA DIRECTORY [=] 'data_dir'] [INDEX DIRECTORY [=] 'index_dir'] [MAX_ROWS [=] max_number_of_rows] [MIN_ROWS [=] min_number_of_rows] [TABLESPACE [=] tablespace_name] [NODEGROUP [=] node_group_id] select_statement: [IGNORE | REPLACE] [AS] SELECT ... (Some valid select statement) CREATE TABLE creates a table with the given name. You must have the CREATE privilege for the table. Rules for permissible table names are given in http://dev.mysql.com/doc/refman/5.5/en/identifiers.html. By default, the table is created in the default database, using the InnoDB storage engine. An error occurs if the table exists, if there is no default database, or if the database does not exist. URL: http://dev.mysql.com/doc/refman/5.5/en/create-table.html 8http://dev.mysql.com/doc/refman/5.5/en/create-table.html>aSyntax: > Greater than: URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html "mysql> SELECT 2 > 2; -> 0 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html ANALYZE TABLESyntax: ANALYZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE tbl_name [, tbl_name] ... ANALYZE TABLE analyzes and stores the key distribution for a table. During the analysis, the table is locked with a read lock for InnoDB and MyISAM. This statement works with InnoDB, NDB, and MyISAM tables. For MyISAM tables, this statement is equivalent to using myisamchk --analyze. For more information on how the analysis works within InnoDB, see http://dev.mysql.com/doc/refman/5.5/en/innodb-restrictions.html. MySQL uses the stored key distribution to decide the order in which tables should be joined when you perform a join on something other than a constant. In addition, key distributions can be used when deciding which indexes to use for a specific table within a query. This statement requires SELECT and INSERT privileges for the table. ANALYZE TABLE is supported for partitioned tables, and you can use ALTER TABLE ... ANALYZE PARTITION to analyze one or more partitions; for more information, see [HELP ALTER TABLE], and http://dev.mysql.com/doc/refman/5.5/en/partitioning-maintenance.html. URL: http://dev.mysql.com/doc/refman/5.5/en/analyze-table.html 9http://dev.mysql.com/doc/refman/5.5/en/analyze-table.html MICROSECONDSyntax: MICROSECOND(expr) Returns the microseconds from the time or datetime expression expr as a number in the range from 0 to 999999. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html mysql> SELECT MICROSECOND('12:00:00.123456'); -> 123456 mysql> SELECT MICROSECOND('2009-12-31 23:59:59.000010'); -> 10 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html CONSTRAINT'kInnoDB supports foreign keys, which let you cross-reference related data across tables, and foreign key constraints, which help keep this spread-out data consistent. The syntax for an InnoDB foreign key constraint definition in the CREATE TABLE or ALTER TABLE statement looks like this: [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name, ...) REFERENCES tbl_name (index_col_name,...) [ON DELETE reference_option] [ON UPDATE reference_option] reference_option: RESTRICT | CASCADE | SET NULL | NO ACTION URL: http://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html CREATE TABLE product (category INT NOT NULL, id INT NOT NULL, price DECIMAL, PRIMARY KEY(category, id)) ENGINE=INNODB; CREATE TABLE customer (id INT NOT NULL, PRIMARY KEY (id)) ENGINE=INNODB; CREATE TABLE product_order (no INT NOT NULL AUTO_INCREMENT, product_category INT NOT NULL, product_id INT NOT NULL, customer_id INT NOT NULL, PRIMARY KEY(no), INDEX (product_category, product_id), FOREIGN KEY (product_category, product_id) REFERENCES product(category, id) ON UPDATE CASCADE ON DELETE RESTRICT, INDEX (customer_id), FOREIGN KEY (customer_id) REFERENCES customer(id)) ENGINE=INNODB; Jhttp://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html\ CREATE SERVER'Syntax: CREATE SERVER server_name FOREIGN DATA WRAPPER wrapper_name OPTIONS (option [, option] ...) option: { HOST character-literal | DATABASE character-literal | USER character-literal | PASSWORD character-literal | SOCKET character-literal | OWNER character-literal | PORT numeric-literal } This statement creates the definition of a server for use with the FEDERATED storage engine. The CREATE SERVER statement creates a new row within the servers table within the mysql database. This statement requires the SUPER privilege. The server_name should be a unique reference to the server. Server definitions are global within the scope of the server, it is not possible to qualify the server definition to a specific database. server_name has a maximum length of 64 characters (names longer than 64 characters are silently truncated), and is case insensitive. You may specify the name as a quoted string. The wrapper_name should be mysql, and may be quoted with single quotation marks. Other values for wrapper_name are not currently supported. For each option you must specify either a character literal or numeric literal. Character literals are UTF-8, support a maximum length of 64 characters and default to a blank (empty) string. String literals are silently truncated to 64 characters. Numeric literals must be a number between 0 and 9999, default value is 0. *Note*: Note that the OWNER option is currently not applied, and has no effect on the ownership or operation of the server connection that is created. The CREATE SERVER statement creates an entry in the mysql.servers table that can later be used with the CREATE TABLE statement when creating a FEDERATED table. The options that you specify will be used to populate the columns in the mysql.servers table. The table columns are Server_name, Host, Db, Username, Password, Port and Socket. URL: http://dev.mysql.com/doc/refman/5.5/en/create-server.html kCREATE SERVER s FOREIGN DATA WRAPPER mysql OPTIONS (USER 'Remote', HOST '192.168.1.106', DATABASE 'test'); 9http://dev.mysql.com/doc/refman/5.5/en/create-server.htmlFIELD%Syntax: FIELD(str,str1,str2,str3,...) Returns the index (position) of str in the str1, str2, str3, ... list. Returns 0 if str is not found. If all arguments to FIELD() are strings, all arguments are compared as strings. If all arguments are numbers, they are compared as numbers. Otherwise, the arguments are compared as double. If str is NULL, the return value is 0 because NULL fails equality comparison with any value. FIELD() is the complement of ELT(). URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT FIELD('ej', 'Hej', 'ej', 'Heja', 'hej', 'foo'); -> 2 mysql> SELECT FIELD('fo', 'Hej', 'ej', 'Heja', 'hej', 'foo'); -> 0 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.htmlOMAKETIMESyntax: MAKETIME(hour,minute,second) Returns a time value calculated from the hour, minute, and second arguments. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html 8mysql> SELECT MAKETIME(12,15,30); -> '12:15:30' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.htmlCURDATESyntax: CURDATE() Returns the current date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html bmysql> SELECT CURDATE(); -> '2008-06-13' mysql> SELECT CURDATE() + 0; -> 20080613 Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html  SET PASSWORD 6 Syntax: SET PASSWORD [FOR user] = { PASSWORD('cleartext password') | OLD_PASSWORD('cleartext password') | 'encrypted password' } The SET PASSWORD statement assigns a password to an existing MySQL user account. When the read_only system variable is enabled, the SUPER privilege is required to use SET PASSWORD, in addition to whatever other privileges might be required. If the password is specified using the PASSWORD() or OLD_PASSWORD() function, the cleartext (unencrypted) password should be given as the argument to the function, which hashes the password and returns the encrypted password string. If the password is specified without using either function, it should be the already encrypted password value as a literal string. In all cases, the encrypted password string must be in the format required by the authentication method used for the account. The old_passwords system variable value determines the hashing method used by PASSWORD(). If you specify the password using that function and SET PASSWORD rejects the password as not being in the correct format, it may be necessary to set old_passwords to change the hashing method. For descriptions of the permitted values, see http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html. With no FOR user clause, this statement sets the password for the current user. (To see which account the server authenticated you as, invoke the CURRENT_USER() function.) Any client who successfully connects to the server using a nonanonymous account can change the password for that account. With a FOR user clause, this statement sets the password for the named user. You must have the UPDATE privilege for the mysql database to do this. The user account name uses the format described in http://dev.mysql.com/doc/refman/5.5/en/account-names.html. The user value should be given as 'user_name'@'host_name', where 'user_name' and 'host_name' are exactly as listed in the User and Host columns of the mysql.user table row. (If you specify only a user name, a host name of '%' is used.) For example, to set the password for an account with User and Host column values of 'bob' and '%.example.org', write the statement like this: SET PASSWORD FOR 'bob'@'%.example.org' = PASSWORD('cleartext password'); URL: http://dev.mysql.com/doc/refman/5.5/en/set-password.html 8http://dev.mysql.com/doc/refman/5.5/en/set-password.html WALTER TABLESPACE' Syntax: ALTER TABLESPACE tablespace_name {ADD|DROP} DATAFILE 'file_name' [INITIAL_SIZE [=] size] [WAIT] ENGINE [=] engine_name This statement can be used either to add a new data file, or to drop a data file from a tablespace. The ADD DATAFILE variant enables you to specify an initial size using an INITIAL_SIZE clause, where size is measured in bytes; the default value is 128M (128 megabytes). You may optionally follow this integer value with a one-letter abbreviation for an order of magnitude, similar to those used in my.cnf. Generally, this is one of the letters M (for megabytes) or G (for gigabytes). *Note*: All MySQL Cluster Disk Data objects share the same namespace. This means that each Disk Data object must be uniquely named (and not merely each Disk Data object of a given type). For example, you cannot have a tablespace and an data file with the same name, or an undo log file and a tablespace with the same name. On 32-bit systems, the maximum supported value for INITIAL_SIZE is 4G. (Bug #29186) INITIAL_SIZE is rounded, explicitly, as for CREATE TABLESPACE. Once a data file has been created, its size cannot be changed; however, you can add more data files to the tablespace using additional ALTER TABLESPACE ... ADD DATAFILE statements. Using DROP DATAFILE with ALTER TABLESPACE drops the data file 'file_name' from the tablespace. You cannot drop a data file from a tablespace which is in use by any table; in other words, the data file must be empty (no extents used). See http://dev.mysql.com/doc/refman/5.5/en/mysql-cluster-disk-data-objects. html. In addition, any data file to be dropped must previously have been added to the tablespace with CREATE TABLESPACE or ALTER TABLESPACE. Both ALTER TABLESPACE ... ADD DATAFILE and ALTER TABLESPACE ... DROP DATAFILE require an ENGINE clause which specifies the storage engine used by the tablespace. Currently, the only accepted values for engine_name are NDB and NDBCLUSTER. WAIT is parsed but otherwise ignored, and so has no effect in MySQL 5.5. It is intended for future expansion. When ALTER TABLESPACE ... ADD DATAFILE is used with ENGINE = NDB, a data file is created on each Cluster data node. You can verify that the data files were created and obtain information about them by querying the INFORMATION_SCHEMA.FILES table. For example, the following query shows all data files belonging to the tablespace named newts: mysql> SELECT LOGFILE_GROUP_NAME, FILE_NAME, EXTRA -> FROM INFORMATION_SCHEMA.FILES -> WHERE TABLESPACE_NAME = 'newts' AND FILE_TYPE = 'DATAFILE'; +--------------------+--------------+----------------+ | LOGFILE_GROUP_NAME | FILE_NAME | EXTRA | +--------------------+--------------+----------------+ | lg_3 | newdata.dat | CLUSTER_NODE=3 | | lg_3 | newdata.dat | CLUSTER_NODE=4 | | lg_3 | newdata2.dat | CLUSTER_NODE=3 | | lg_3 | newdata2.dat | CLUSTER_NODE=4 | +--------------------+--------------+----------------+ 2 rows in set (0.03 sec) See http://dev.mysql.com/doc/refman/5.5/en/files-table.html. ALTER TABLESPACE is useful only with Disk Data storage for MySQL Cluster. See http://dev.mysql.com/doc/refman/5.5/en/mysql-cluster-disk-data.html. URL: http://dev.mysql.com/doc/refman/5.5/en/alter-tablespace.html <http://dev.mysql.com/doc/refman/5.5/en/alter-tablespace.html IF FUNCTION$Syntax: IF(expr1,expr2,expr3) If expr1 is TRUE (expr1 <> 0 and expr1 <> NULL) then IF() returns expr2; otherwise it returns expr3. IF() returns a numeric or string value, depending on the context in which it is used. URL: http://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.html mysql> SELECT IF(1>2,2,3); -> 3 mysql> SELECT IF(1<2,'yes','no'); -> 'yes' mysql> SELECT IF(STRCMP('test','test1'),'no','yes'); -> 'no' Bhttp://dev.mysql.com/doc/refman/5.5/en/control-flow-functions.htmlENUMENUM('value1','value2',...) [CHARACTER SET charset_name] [COLLATE collation_name] An enumeration. A string object that can have only one value, chosen from the list of values 'value1', 'value2', ..., NULL or the special '' error value. An ENUM column can have a maximum of 65,535 distinct values. ENUM values are represented internally as integers. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html.DATABASESyntax: DATABASE() Returns the default (current) database name as a string in the utf8 character set. If there is no default database, DATABASE() returns NULL. Within a stored routine, the default database is the database that the routine is associated with, which is not necessarily the same as the database that is the default in the calling context. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html ,mysql> SELECT DATABASE(); -> 'test' Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html$ POINTFROMWKB PointFromWKB(wkb[,srid]) Constructs a POINT value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#gis-wkb-functionsPOWER{Syntax: POWER(X,Y) This is a synonym for POW(). URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlZATANSyntax: ATAN(X) Returns the arc tangent of X, that is, the value whose tangent is X. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html fmysql> SELECT ATAN(2); -> 1.1071487177941 mysql> SELECT ATAN(-2); -> -1.1071487177941 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlSTRCMP%Syntax: STRCMP(expr1,expr2) STRCMP() returns 0 if the strings are the same, -1 if the first argument is smaller than the second according to the current sort order, and 1 otherwise. URL: http://dev.mysql.com/doc/refman/5.5/en/string-comparison-functions.html mysql> SELECT STRCMP('text', 'text2'); -> -1 mysql> SELECT STRCMP('text2', 'text'); -> 1 mysql> SELECT STRCMP('text', 'text'); -> 0 Ghttp://dev.mysql.com/doc/refman/5.5/en/string-comparison-functions.htmlINSERT DELAYEDaSyntax: INSERT DELAYED ... The DELAYED option for the INSERT statement is a MySQL extension to standard SQL that is very useful if you have clients that cannot or need not wait for the INSERT to complete. This is a common situation when you use MySQL for logging and you also periodically run SELECT and UPDATE statements that take a long time to complete. When a client uses INSERT DELAYED, it gets an okay from the server at once, and the row is queued to be inserted when the table is not in use by any other thread. Another major benefit of using INSERT DELAYED is that inserts from many clients are bundled together and written in one block. This is much faster than performing many separate inserts. Note that INSERT DELAYED is slower than a normal INSERT if the table is not otherwise in use. There is also the additional overhead for the server to handle a separate thread for each table for which there are delayed rows. This means that you should use INSERT DELAYED only when you are really sure that you need it. The queued rows are held only in memory until they are inserted into the table. This means that if you terminate mysqld forcibly (for example, with kill -9) or if mysqld dies unexpectedly, any queued rows that have not been written to disk are lost. There are some constraints on the use of DELAYED: o INSERT DELAYED works only with MyISAM, MEMORY, ARCHIVE, and BLACKHOLE tables. For engines that do not support DELAYED, an error occurs. o An error occurs for INSERT DELAYED if used with a table that has been locked with LOCK TABLES because the insert must be handled by a separate thread, not by the session that holds the lock. o For MyISAM tables, if there are no free blocks in the middle of the data file, concurrent SELECT and INSERT statements are supported. Under these circumstances, you very seldom need to use INSERT DELAYED with MyISAM. o INSERT DELAYED should be used only for INSERT statements that specify value lists. The server ignores DELAYED for INSERT ... SELECT or INSERT ... ON DUPLICATE KEY UPDATE statements. o Because the INSERT DELAYED statement returns immediately, before the rows are inserted, you cannot use LAST_INSERT_ID() to get the AUTO_INCREMENT value that the statement might generate. o DELAYED rows are not visible to SELECT statements until they actually have been inserted. o Prior to MySQL 5.5.7, INSERT DELAYED was treated as a normal INSERT if the statement inserted multiple rows, binary logging was enabled, and the global logging format was statement-based (that is, whenever binlog_format was set to STATEMENT). Beginning with MySQL 5.5.7, INSERT DELAYED is always handled as a simple INSERT (that is, without the DELAYED option) whenever the value of binlog_format is STATEMENT or MIXED. (In the latter case, the statement no longer triggers a switch to row-based logging, and so is logged using the statement-based format.) This does not apply when using row-based binary logging mode (binlog_format set to ROW), in which INSERT DELAYED statements are always executed using the DELAYED option as specified, and logged as row-update events. o DELAYED is ignored on slave replication servers, so that INSERT DELAYED is treated as a normal INSERT on slaves. This is because DELAYED could cause the slave to have different data than the master. o Pending INSERT DELAYED statements are lost if a table is write locked and ALTER TABLE is used to modify the table structure. o INSERT DELAYED is not supported for views. o INSERT DELAYED is not supported for partitioned tables. URL: http://dev.mysql.com/doc/refman/5.5/en/insert-delayed.html :http://dev.mysql.com/doc/refman/5.5/en/insert-delayed.html SHOW PROFILE Syntax: SHOW PROFILE [type [, type] ... ] [FOR QUERY n] [LIMIT row_count [OFFSET offset]] type: ALL | BLOCK IO | CONTEXT SWITCHES | CPU | IPC | MEMORY | PAGE FAULTS | SOURCE | SWAPS The SHOW PROFILE and SHOW PROFILES statements display profiling information that indicates resource usage for statements executed during the course of the current session. Profiling is controlled by the profiling session variable, which has a default value of 0 (OFF). Profiling is enabled by setting profiling to 1 or ON: mysql> SET profiling = 1; SHOW PROFILES displays a list of the most recent statements sent to the server. The size of the list is controlled by the profiling_history_size session variable, which has a default value of 15. The maximum value is 100. Setting the value to 0 has the practical effect of disabling profiling. All statements are profiled except SHOW PROFILE and SHOW PROFILES, so you will find neither of those statements in the profile list. Malformed statements are profiled. For example, SHOW PROFILING is an illegal statement, and a syntax error occurs if you try to execute it, but it will show up in the profiling list. SHOW PROFILE displays detailed information about a single statement. Without the FOR QUERY n clause, the output pertains to the most recently executed statement. If FOR QUERY n is included, SHOW PROFILE displays information for statement n. The values of n correspond to the Query_ID values displayed by SHOW PROFILES. The LIMIT row_count clause may be given to limit the output to row_count rows. If LIMIT is given, OFFSET offset may be added to begin the output offset rows into the full set of rows. By default, SHOW PROFILE displays Status and Duration columns. The Status values are like the State values displayed by SHOW PROCESSLIST, although there might be some minor differences in interpretion for the two statements for some status values (see http://dev.mysql.com/doc/refman/5.5/en/thread-information.html). Optional type values may be specified to display specific additional types of information: o ALL displays all information o BLOCK IO displays counts for block input and output operations o CONTEXT SWITCHES displays counts for voluntary and involuntary context switches o CPU displays user and system CPU usage times o IPC displays counts for messages sent and received o MEMORY is not currently implemented o PAGE FAULTS displays counts for major and minor page faults o SOURCE displays the names of functions from the source code, together with the name and line number of the file in which the function occurs o SWAPS displays swap counts Profiling is enabled per session. When a session ends, its profiling information is lost. URL: http://dev.mysql.com/doc/refman/5.5/en/show-profile.html mysql> SELECT @@profiling; +-------------+ | @@profiling | +-------------+ | 0 | +-------------+ 1 row in set (0.00 sec) mysql> SET profiling = 1; Query OK, 0 rows affected (0.00 sec) mysql> DROP TABLE IF EXISTS t1; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> CREATE TABLE T1 (id INT); Query OK, 0 rows affected (0.01 sec) mysql> SHOW PROFILES; +----------+----------+--------------------------+ | Query_ID | Duration | Query | +----------+----------+--------------------------+ | 0 | 0.000088 | SET PROFILING = 1 | | 1 | 0.000136 | DROP TABLE IF EXISTS t1 | | 2 | 0.011947 | CREATE TABLE t1 (id INT) | +----------+----------+--------------------------+ 3 rows in set (0.00 sec) mysql> SHOW PROFILE; +----------------------+----------+ | Status | Duration | +----------------------+----------+ | checking permissions | 0.000040 | | creating table | 0.000056 | | After create | 0.011363 | | query end | 0.000375 | | freeing items | 0.000089 | | logging slow query | 0.000019 | | cleaning up | 0.000005 | +----------------------+----------+ 7 rows in set (0.00 sec) mysql> SHOW PROFILE FOR QUERY 1; +--------------------+----------+ | Status | Duration | +--------------------+----------+ | query end | 0.000107 | | freeing items | 0.000008 | | logging slow query | 0.000015 | | cleaning up | 0.000006 | +--------------------+----------+ 4 rows in set (0.00 sec) mysql> SHOW PROFILE CPU FOR QUERY 2; +----------------------+----------+----------+------------+ | Status | Duration | CPU_user | CPU_system | +----------------------+----------+----------+------------+ | checking permissions | 0.000040 | 0.000038 | 0.000002 | | creating table | 0.000056 | 0.000028 | 0.000028 | | After create | 0.011363 | 0.000217 | 0.001571 | | query end | 0.000375 | 0.000013 | 0.000028 | | freeing items | 0.000089 | 0.000010 | 0.000014 | | logging slow query | 0.000019 | 0.000009 | 0.000010 | | cleaning up | 0.000005 | 0.000003 | 0.000002 | +----------------------+----------+----------+------------+ 7 rows in set (0.00 sec) 8http://dev.mysql.com/doc/refman/5.5/en/show-profile.htmlSHOW PROCEDURE CODESyntax: SHOW PROCEDURE CODE proc_name This statement is a MySQL extension that is available only for servers that have been built with debugging support. It displays a representation of the internal implementation of the named stored procedure. A similar statement, SHOW FUNCTION CODE, displays information about stored functions (see [HELP SHOW FUNCTION CODE]). Both statements require that you be the owner of the routine or have SELECT access to the mysql.proc table. If the named routine is available, each statement produces a result set. Each row in the result set corresponds to one "instruction" in the routine. The first column is Pos, which is an ordinal number beginning with 0. The second column is Instruction, which contains an SQL statement (usually changed from the original source), or a directive which has meaning only to the stored-routine handler. URL: http://dev.mysql.com/doc/refman/5.5/en/show-procedure-code.html mysql> DELIMITER // mysql> CREATE PROCEDURE p1 () -> BEGIN -> DECLARE fanta INT DEFAULT 55; -> DROP TABLE t2; -> LOOP -> INSERT INTO t3 VALUES (fanta); -> END LOOP; -> END// Query OK, 0 rows affected (0.00 sec) mysql> SHOW PROCEDURE CODE p1// +-----+----------------------------------------+ | Pos | Instruction | +-----+----------------------------------------+ | 0 | set fanta@0 55 | | 1 | stmt 9 "DROP TABLE t2" | | 2 | stmt 5 "INSERT INTO t3 VALUES (fanta)" | | 3 | jump 2 | +-----+----------------------------------------+ 4 rows in set (0.00 sec) ?http://dev.mysql.com/doc/refman/5.5/en/show-procedure-code.html MEDIUMTEXTMEDIUMTEXT [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 16,777,215 (224 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. Each MEDIUMTEXT value is stored using a 3-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.5/en/string-type-overview.htmlLNSyntax: LN(X) Returns the natural logarithm of X; that is, the base-e logarithm of X. If X is less than or equal to 0, then NULL is returned. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Wmysql> SELECT LN(2); -> 0.69314718055995 mysql> SELECT LN(-2); -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlRETURNSyntax: RETURN expr The RETURN statement terminates execution of a stored function and returns the value expr to the function caller. There must be at least one RETURN statement in a stored function. There may be more than one if the function has multiple exit points. This statement is not used in stored procedures, triggers, or events. The LEAVE statement can be used to exit a stored program of those types. URL: http://dev.mysql.com/doc/refman/5.5/en/return.html 2http://dev.mysql.com/doc/refman/5.5/en/return.htmlSHOW COLLATIONESyntax: SHOW COLLATION [LIKE 'pattern' | WHERE expr] This statement lists collations supported by the server. By default, the output from SHOW COLLATION includes all available collations. The LIKE clause, if present, indicates which collation names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. For example: mysql> SHOW COLLATION LIKE 'latin1%'; +-------------------+---------+----+---------+----------+---------+ | Collation | Charset | Id | Default | Compiled | Sortlen | +-------------------+---------+----+---------+----------+---------+ | latin1_german1_ci | latin1 | 5 | | | 0 | | latin1_swedish_ci | latin1 | 8 | Yes | Yes | 0 | | latin1_danish_ci | latin1 | 15 | | | 0 | | latin1_german2_ci | latin1 | 31 | | Yes | 2 | | latin1_bin | latin1 | 47 | | Yes | 0 | | latin1_general_ci | latin1 | 48 | | | 0 | | latin1_general_cs | latin1 | 49 | | | 0 | | latin1_spanish_ci | latin1 | 94 | | | 0 | +-------------------+---------+----+---------+----------+---------+ URL: http://dev.mysql.com/doc/refman/5.5/en/show-collation.html :http://dev.mysql.com/doc/refman/5.5/en/show-collation.htmlLOGFSyntax: LOG(X), LOG(B,X) If called with one parameter, this function returns the natural logarithm of X. If X is less than or equal to 0, then NULL is returned. The inverse of this function (when called with a single argument) is the EXP() function. URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html Ymysql> SELECT LOG(2); -> 0.69314718055995 mysql> SELECT LOG(-2); -> NULL Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlISET SQL_LOG_BINSyntax: SET sql_log_bin = {0|1} The sql_log_bin variable controls whether logging to the binary log is done. The default value is 1 (do logging). To change logging for the current session, change the session value of this variable. The session user must have the SUPER privilege to set this variable. Beginning with MySQL 5.5.5, it is no longer possible to set @@session.sql_log_bin within a transaction or subquery. (Bug #53437) URL: http://dev.mysql.com/doc/refman/5.5/en/set-sql-log-bin.html ;http://dev.mysql.com/doc/refman/5.5/en/set-sql-log-bin.html7!=cSyntax: <>, != Not equal: URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html mysql> SELECT '.01' <> '0.01'; -> 1 mysql> SELECT .01 <> '0.01'; -> 0 mysql> SELECT 'zapp' <> 'zappp'; -> 1 @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlWHILESyntax: [begin_label:] WHILE search_condition DO statement_list END WHILE [end_label] The statement list within a WHILE statement is repeated as long as the search_condition expression is true. statement_list consists of one or more SQL statements, each terminated by a semicolon (;) statement delimiter. A WHILE statement can be labeled. For the rules regarding label use, see [HELP labels]. URL: http://dev.mysql.com/doc/refman/5.5/en/while.html CREATE PROCEDURE dowhile() BEGIN DECLARE v1 INT DEFAULT 5; WHILE v1 > 0 DO ... SET v1 = v1 - 1; END WHILE; END; 1http://dev.mysql.com/doc/refman/5.5/en/while.html` AES_DECRYPT Syntax: AES_DECRYPT(crypt_str,key_str) This function decrypts data using the official AES (Advanced Encryption Standard) algorithm. For more information, see the description of AES_ENCRYPT(). URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.htmlDAYNAME)Syntax: DAYNAME(date) Returns the name of the weekday for date. The language used for the name is controlled by the value of the lc_time_names system variable (http://dev.mysql.com/doc/refman/5.5/en/locale-support.html). URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html ;mysql> SELECT DAYNAME('2007-02-03'); -> 'Saturday' Chttp://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html COERCIBILITYSyntax: COERCIBILITY(str) Returns the collation coercibility value of the string argument. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html mysql> SELECT COERCIBILITY('abc' COLLATE latin1_swedish_ci); -> 0 mysql> SELECT COERCIBILITY(USER()); -> 3 mysql> SELECT COERCIBILITY('abc'); -> 4 Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.html&INTINT[(M)] [UNSIGNED] [ZEROFILL] A normal-size integer. The signed range is -2147483648 to 2147483647. The unsigned range is 0 to 4294967295. URL: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.htmlUGLENGTH GLength(ls) Returns as a double-precision number the length of the LineString value ls in its associated spatial reference. URL: http://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functions mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT GLength(GeomFromText(@ls)); +----------------------------+ | GLength(GeomFromText(@ls)) | +----------------------------+ | 2.8284271247462 | +----------------------------+ ehttp://dev.mysql.com/doc/refman/5.5/en/geometry-property-functions.html#linestring-property-functionsQRADIANSSyntax: RADIANS(X) Returns the argument X, converted from degrees to radians. (Note that π radians equals 180 degrees.) URL: http://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.html 6mysql> SELECT RADIANS(90); -> 1.5707963267949 Bhttp://dev.mysql.com/doc/refman/5.5/en/mathematical-functions.htmlh COLLATIONSyntax: COLLATION(str) Returns the collation of the string argument. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html mysql> SELECT COLLATION('abc'); -> 'latin1_swedish_ci' mysql> SELECT COLLATION(_utf8'abc'); -> 'utf8_general_ci' Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.htmlwCOALESCESyntax: COALESCE(value,...) Returns the first non-NULL value in the list, or NULL if there are no non-NULL values. URL: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html emysql> SELECT COALESCE(NULL,1); -> 1 mysql> SELECT COALESCE(NULL,NULL,NULL); -> NULL @http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.htmlVERSIONzSyntax: VERSION() Returns a string that indicates the MySQL server version. The string uses the utf8 character set. The value might have a suffix in addition to the version number. See the description of the version system variable in http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html. URL: http://dev.mysql.com/doc/refman/5.5/en/information-functions.html 6mysql> SELECT VERSION(); -> '5.5.29-standard' Ahttp://dev.mysql.com/doc/refman/5.5/en/information-functions.htmlMAKE_SET%vSyntax: MAKE_SET(bits,str1,str2,...) Returns a set value (a string containing substrings separated by "," characters) consisting of the strings that have the corresponding bit in bits set. str1 corresponds to bit 0, str2 to bit 1, and so on. NULL values in str1, str2, ... are not appended to the result. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html mysql> SELECT MAKE_SET(1,'a','b','c'); -> 'a' mysql> SELECT MAKE_SET(1 | 4,'hello','nice','world'); -> 'hello,world' mysql> SELECT MAKE_SET(1 | 4,'hello','nice',NULL,'world'); -> 'hello' mysql> SELECT MAKE_SET(0,'a','b','c'); -> '' <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html FIND_IN_SET%Syntax: FIND_IN_SET(str,strlist) Returns a value in the range of 1 to N if the string str is in the string list strlist consisting of N substrings. A string list is a string composed of substrings separated by "," characters. If the first argument is a constant string and the second is a column of type SET, the FIND_IN_SET() function is optimized to use bit arithmetic. Returns 0 if str is not in strlist or if strlist is the empty string. Returns NULL if either argument is NULL. This function does not work properly if the first argument contains a comma (",") character. URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html 7mysql> SELECT FIND_IN_SET('b','a,b,c,d'); -> 2 <http://dev.mysql.com/doc/refman/5.5/en/string-functions.html