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| From: | paul | Date: | May 8 2008 6:55pm |
| Subject: | svn commit - mysqldoc@docsrva: r10692 - in trunk: . it/refman-5.1 pt/refman-5.1 refman-5.1 refman-6.0 | ||
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Author: paul Date: 2008-05-08 18:55:11 +0200 (Thu, 08 May 2008) New Revision: 10692 Log: r31247@frost: paul | 2008-05-08 10:52:57 -0500 events: general revisions Modified: trunk/it/refman-5.1/events.xml trunk/pt/refman-5.1/events.xml trunk/refman-5.1/events.xml trunk/refman-6.0/events.xml Property changes on: trunk ___________________________________________________________________ Name: svk:merge - 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:35828 7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:31245 b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218 bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:31182 + 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:35828 7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:31247 b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218 bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:31182 Modified: trunk/it/refman-5.1/events.xml =================================================================== --- trunk/it/refman-5.1/events.xml 2008-05-08 15:40:57 UTC (rev 10691) +++ trunk/it/refman-5.1/events.xml 2008-05-08 16:55:11 UTC (rev 10692) Changed blocks: 25, Lines Added: 114, Lines Deleted: 119; 18858 bytes @@ -68,8 +68,7 @@ <listitem> <para> <xref linkend="events-limitations-restrictions"/>, describes the - restrictions and limitations of MySQL's Event Scheduler - implementation. + restrictions and limitations on the use of events. </para> </listitem> @@ -214,8 +213,9 @@ thread</firstterm>; when we refer to the Event Scheduler, we actually refer to this thread. When running, the event scheduler thread and its current state can be seen by users having the - <literal>SUPER</literal> privilege in the output of <literal>SHOW - PROCESSLIST</literal>, as shown in the discussion that follows. + <literal>PROCESS</literal> privilege in the output of + <literal>SHOW PROCESSLIST</literal>, as shown in the discussion + that follows. </para> <indexterm> @@ -231,6 +231,9 @@ <para id="events-event-scheduler-option"> The global variable <literal>event_scheduler</literal> determines whether the Event Scheduler is enabled and running on the server. + affect event scheduling as described here: The global + <literal>event_scheduler</literal> system variable determines + whether the Event Scheduler is enabled and running on the server. Beginning with MySQL 5.1.12, it has one of these 3 values, which affect event scheduling as described here: </para> @@ -308,15 +311,17 @@ Scheduler non-operational. When the Event Scheduler is <literal>DISABLED</literal>, the event scheduler thread does not run (and so does not appear in the output of <literal>SHOW - PROCESSLIST</literal>). + PROCESSLIST</literal>). In addition, the Event Scheduler state + cannot be changed at runtime. </para> </listitem> </itemizedlist> <para> - When the server is running<literal>event_scheduler</literal> can - be toggled between <literal>ON</literal> and + If the Event Scheduler status has not been set to + <literal>DISABLED</literal>, <literal>event_scheduler</literal> + can be toggled between <literal>ON</literal> and <literal>OFF</literal> (using <literal>SET</literal>). It is also possible to use <literal>0</literal> for <literal>OFF</literal>, and <literal>1</literal> for <literal>ON</literal> when setting @@ -370,14 +375,14 @@ <important> <para> - It is not possible to enable or disable the Event Scheduler when - the server is running. That is, you can change the value of - <literal>event_scheduler</literal> to - <literal>DISABLED</literal> — or from - <literal>DISABLED</literal> to one of the other permitted values - for this option — only when the server is stopped. - Attempting to do so when the server is running fails with an - error. + It is possible to set the Event Scheduler to + <literal>DISABLED</literal> only at server startup. If + <literal>event_scheduler</literal> is <literal>ON</literal> or + <literal>OFF</literal>, you cannot set it to + <literal>DISABLED</literal> at runtime. Also, if the Event + Scheduler is set to <literal>DISABLED</literal> at startup, you + cannot change the value of <literal>event_scheduler</literal> at + runtime. </para> </important> @@ -415,11 +420,11 @@ <para> To enable the Event Scheduler, restart the server without the - <option>--event-scheduler=<replaceable>DISABLED</replaceable></option> - command line option, or after removing or commenting out the line - containing <literal>event_scheduler=DISABLED</literal> in the - server configuration file, as appropriate. Alternatively, you can - use <literal>ON</literal> (or <literal>1</literal>) or + <option>--event-scheduler=DISABLED</option> command-line option, + or after removing or commenting out the line containing + <literal>event_scheduler=DISABLED</literal> in the server + configuration file, as appropriate. Alternatively, you can use + <literal>ON</literal> (or <literal>1</literal>) or <literal>OFF</literal> (or <literal>0</literal>) in place of the <literal>DISABLED</literal> value when starting the server. </para> @@ -559,7 +564,7 @@ <para> An event can be deleted by any user having the <literal>EVENT</literal> privilege for the database on which - the event is defined. Prior to MySQL 5.12, a user other than + the event is defined. Prior to MySQL 5.1.12, a user other than the definer required privileges on the <literal>mysql.event</literal> table. See <xref linkend="events-privileges"/>. @@ -683,6 +688,32 @@ </programlisting> <para> + It is possible to change multiple characteristics of an event in + a single statement. This example changes the SQL statement + executed by <literal>myevent</literal> to one that deletes all + records from <literal>mytable</literal>; it also changes the + schedule for the event such that it executes once, one day after + this <literal>ALTER EVENT</literal> statement is run. + </para> + +<programlisting> +ALTER TABLE myevent + ON SCHEDULE + AT CURRENT_TIMESTAMP + INTERVAL 1 DAY + DO + TRUNCATE TABLE myschema.mytable; +</programlisting> + + <para> + It is necessary to include only those options in an + <literal>ALTER EVENT</literal> statement which correspond to + characteristics that you actually wish to change; options which + are omitted retain their existing values. This includes any + default values for <literal>CREATE EVENT</literal> such as + <literal>ENABLE</literal>. + </para> + + <para> To disable <literal>myevent</literal>, use this <literal>ALTER EVENT</literal> statement: </para> @@ -716,25 +747,10 @@ </para> <para> - It is possible to change multiple characteristics of an event in - a single statement. This example changes the SQL statement - executed by <literal>myevent</literal> to one that deletes all - records from <literal>mytable</literal>; it also changes the - schedule for the event such that it executes once, one day after - this <literal>ALTER EVENT</literal> statement is run. - </para> - -<programlisting> -ALTER TABLE myevent - ON SCHEDULE - AT CURRENT_TIMESTAMP + INTERVAL 1 DAY - DO - TRUNCATE TABLE myschema.mytable; -</programlisting> - - <para> To rename an event, use the <literal>ALTER EVENT</literal> - statement's <literal>RENAME TO</literal> clause, as shown here: + statement's <literal>RENAME TO</literal> clause. This statement + renames the event <literal>myevent</literal> to + <literal>yourevent</literal>: </para> <programlisting> @@ -743,20 +759,9 @@ </programlisting> <para> - The previous statement renames the event - <literal>myevent</literal> to <literal>yourevent</literal>. - - <note> - <para> - There is no <literal>RENAME EVENT</literal> statement. - </para> - </note> - </para> - - <para> You can also move an event to a different database using <literal>ALTER EVENT ... RENAME TO ...</literal> and - <literal><replaceable>db_name.table_name</replaceable></literal> + <literal><replaceable>db_name.event_name</replaceable></literal> notation, as shown here: </para> @@ -766,11 +771,17 @@ </programlisting> <para> - In order to execute the previous statement, the user executing - it must have the <literal>EVENT</literal> privilege on both the + To execute the previous statement, the user executing it must + have the <literal>EVENT</literal> privilege on both the <literal>olddb</literal> and <literal>newdb</literal> databases. </para> + <note> + <para> + There is no <literal>RENAME EVENT</literal> statement. + </para> + </note> + <para> Beginning with MySQL 5.1.18, a third value may also appear in place of <literal>ENABLED</literal> or @@ -785,15 +796,6 @@ information. </para> - <para> - It is necessary to include only those options in an - <literal>ALTER EVENT</literal> statement which correspond to - characteristics that you actually wish to change; options which - are omitted retain their existing values. This includes any - default values for <literal>CREATE EVENT</literal> such as - <literal>ENABLE</literal>. - </para> - </section> <section id="create-event"> @@ -837,10 +839,10 @@ DO <replaceable>sql_statement</replaceable>; <replaceable>schedule</replaceable>: - AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] + AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] ... | EVERY <replaceable>interval</replaceable> - [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] - [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] + [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] + [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] <replaceable>interval</replaceable>: <replaceable>quantity</replaceable> {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE | @@ -862,12 +864,8 @@ <para> The keywords <literal>CREATE EVENT</literal> plus an event name, which uniquely identifies the event in the current - schema. - </para> - - <para> - (Prior to MySQL 5.1.12, the event name needed to be unique - only among events created by the same user on a given + schema. (Prior to MySQL 5.1.12, the event name needed to be + unique only among events created by the same user on a given database.) </para> </listitem> @@ -922,8 +920,8 @@ <para> If no schema is indicated as part of - <replaceable>event_name</replaceable>, then the default - (current) schema is assumed. + <replaceable>event_name</replaceable>, the default (current) + schema is assumed. </para> <remark role="help-description-end"/> @@ -946,8 +944,9 @@ format (the same format used in the <literal>GRANT</literal> statement). The <replaceable>user_name</replaceable> and <replaceable>host_name</replaceable> values both are required. - <function role="sql">CURRENT_USER</function> also can be given - as <function role="sql">CURRENT_USER()</function>. The default + The definer can also be given as + <function role="sql">CURRENT_USER</function> or + <function role="sql">CURRENT_USER()</function>. The default <literal>DEFINER</literal> value is the user who executes the <literal>CREATE EVENT</literal> statement. (This is the same as <literal>DEFINER = CURRENT_USER</literal>.) @@ -961,9 +960,9 @@ </para> <para> - <literal>IF NOT EXISTS</literal> functions in the same fashion - with <literal>CREATE EVENT</literal> as it does when used with a - <literal>CREATE TABLE</literal> statement; if an event named + <literal>IF NOT EXISTS</literal> has the same meaning for + <literal>CREATE EVENT</literal> as for <literal>CREATE + TABLE</literal>: If an event named <replaceable>event_name</replaceable> already exists in the same schema, no action is taken, and no error results. (However, a warning is generated in such cases.) @@ -982,11 +981,11 @@ <para> <literal>AT <replaceable>timestamp</replaceable></literal> is used for a one-time event. It specifies that the event - executes one time only at the date and time, given as the + executes one time only at the date and time given by <replaceable>timestamp</replaceable>, which must include both the date and time, or must be an expression that - resolves to a datetime value. You may use a value which is - of either the <literal>DATETIME</literal> or + resolves to a datetime value. You may use a value of either + the <literal>DATETIME</literal> or <literal>TIMESTAMP</literal> type for this purpose. If the date is in the past, a warning occurs, as shown here: </para> @@ -1028,11 +1027,10 @@ </para> <para> - In order to create an event which occurs at some point in - the future relative to the current date and time — - such as that expressed by the phrase <quote>three weeks from - now</quote> — you can use the optional clause - <literal>+ INTERVAL + To create an event which occurs at some point in the future + relative to the current date and time — such as that + expressed by the phrase <quote>three weeks from now</quote> + — you can use the optional clause <literal>+ INTERVAL <replaceable>interval</replaceable></literal>. The <replaceable>interval</replaceable> portion consists of two parts, a quantity and a unit of time, and follows the same @@ -1040,14 +1038,13 @@ <function role="sql">DATE_ADD()</function> function (see <xref linkend="date-and-time-functions"/>. The units keywords are also the same, except that you cannot use any - units involving microseconds when defining an event. + units involving microseconds when defining an event. With + some interval types, complex time units may be used. For + example, <quote>two minutes and ten seconds</quote> can be + expressed as <literal>+ INTERVAL '2:10' + MINUTE_SECOND</literal>. </para> - <remark role="note"> - The following does not produce a syntax error, so if it is - wrong, then it should do so. - </remark> - <para> You can also combine intervals. For example, <literal>AT CURRENT_TIMESTAMP + INTERVAL 3 WEEK + INTERVAL 2 @@ -1059,8 +1056,8 @@ <listitem> <para> - For actions which are to be repeated at a regular interval, - you can use an <literal>EVERY</literal> clause. The + To repeat actions at a regular interval, use an + <literal>EVERY</literal> clause. The <literal>EVERY</literal> keyword is followed by an <replaceable>interval</replaceable> as described in the previous dicussion of the <literal>AT</literal> keyword. @@ -1071,12 +1068,10 @@ </para> <para> - It is not possible to combine <literal>+ INTERVAL</literal> - clauses in a single <literal>EVERY</literal> clause; - however, you can use the same complex time units allowed in - a <literal>+ INTERVAL</literal>. For example, <quote>every - two minutes and ten seconds</quote> can be expressed as - <literal>EVERY '2:10' MINUTE_SECOND</literal>. + Although <literal>+ INTERVAL</literal> clauses are not + allowed in an <literal>EVERY</literal> clause, you can use + the same complex time units allowed in a <literal>+ + INTERVAL</literal>. </para> <para> @@ -1247,29 +1242,29 @@ <note> <para> - The <literal>SHOW</literal> statement and - <literal>SELECT</literal> statements that merely return a - result set have no effect when used in an event; the output - from these is not sent to the MySQL Monitor, nor is it stored - anywhere. However, you can use statements such as - <literal>SELECT INTO</literal> and <literal>INSERT ... - SELECT</literal> that store a result. (See the next example in - this section for an instance of the latter.) + Statements such as <literal>SELECT</literal> or + <literal>SHOW</literal> that merely return a result set have + no effect when used in an event; the output from these is not + sent to the MySQL Monitor, nor is it stored anywhere. However, + you can use statements such as <literal>SELECT ... + INTO</literal> and <literal>INSERT INTO ... SELECT</literal> + that store a result. (See the next example in this section for + an instance of the latter.) </para> </note> <para> - Any reference in the <literal>DO</literal> clause to a table in - other than the same database schema to which the event belongs - must be qualified with the name of the schema in which the table - occurs. (In MySQL 5.1.6, all tables referenced in event - <literal>DO</literal> clauses had to include a reference to the - database.) + The schema to which an event belongs is the default schema for + table references in the <literal>DO</literal> clause. Any + references to tables in other schemas must be qualified with the + proper schema name. (In MySQL 5.1.6, all tables referenced in + event <literal>DO</literal> clauses had to include a reference + to the schema.) </para> <para> - As with stored routines, you can use multiple statements in the - <literal>DO</literal> clause by bracketing them with the + As with stored routines, you can use compound-statement syntax + in the <literal>DO</literal> clause by using the <literal>BEGIN</literal> and <literal>END</literal> keywords, as shown here: </para> @@ -1293,7 +1288,7 @@ </programlisting> <para> - Note the use of the <literal>DELIMITER</literal> statement to + Note the use of the <literal>DELIMITER</literal> command to change the statement delimiter, as with stored routines. See <xref linkend="create-procedure"/>. </para> @@ -1566,8 +1561,8 @@ <para> To enable or disable the execution of scheduled events, it is necessary to set the value of the global - <literal>event_scheduler</literal> variable. This requires the - <literal>SUPER</literal> privilege. + <literal>event_scheduler</literal> system variable. This requires + the <literal>SUPER</literal> privilege. </para> <para> Modified: trunk/pt/refman-5.1/events.xml =================================================================== --- trunk/pt/refman-5.1/events.xml 2008-05-08 15:40:57 UTC (rev 10691) +++ trunk/pt/refman-5.1/events.xml 2008-05-08 16:55:11 UTC (rev 10692) Changed blocks: 25, Lines Added: 114, Lines Deleted: 119; 18858 bytes @@ -68,8 +68,7 @@ <listitem> <para> <xref linkend="events-limitations-restrictions"/>, describes the - restrictions and limitations of MySQL's Event Scheduler - implementation. + restrictions and limitations on the use of events. </para> </listitem> @@ -214,8 +213,9 @@ thread</firstterm>; when we refer to the Event Scheduler, we actually refer to this thread. When running, the event scheduler thread and its current state can be seen by users having the - <literal>SUPER</literal> privilege in the output of <literal>SHOW - PROCESSLIST</literal>, as shown in the discussion that follows. + <literal>PROCESS</literal> privilege in the output of + <literal>SHOW PROCESSLIST</literal>, as shown in the discussion + that follows. </para> <indexterm> @@ -231,6 +231,9 @@ <para id="events-event-scheduler-option"> The global variable <literal>event_scheduler</literal> determines whether the Event Scheduler is enabled and running on the server. + affect event scheduling as described here: The global + <literal>event_scheduler</literal> system variable determines + whether the Event Scheduler is enabled and running on the server. Beginning with MySQL 5.1.12, it has one of these 3 values, which affect event scheduling as described here: </para> @@ -308,15 +311,17 @@ Scheduler non-operational. When the Event Scheduler is <literal>DISABLED</literal>, the event scheduler thread does not run (and so does not appear in the output of <literal>SHOW - PROCESSLIST</literal>). + PROCESSLIST</literal>). In addition, the Event Scheduler state + cannot be changed at runtime. </para> </listitem> </itemizedlist> <para> - When the server is running<literal>event_scheduler</literal> can - be toggled between <literal>ON</literal> and + If the Event Scheduler status has not been set to + <literal>DISABLED</literal>, <literal>event_scheduler</literal> + can be toggled between <literal>ON</literal> and <literal>OFF</literal> (using <literal>SET</literal>). It is also possible to use <literal>0</literal> for <literal>OFF</literal>, and <literal>1</literal> for <literal>ON</literal> when setting @@ -370,14 +375,14 @@ <important> <para> - It is not possible to enable or disable the Event Scheduler when - the server is running. That is, you can change the value of - <literal>event_scheduler</literal> to - <literal>DISABLED</literal> — or from - <literal>DISABLED</literal> to one of the other permitted values - for this option — only when the server is stopped. - Attempting to do so when the server is running fails with an - error. + It is possible to set the Event Scheduler to + <literal>DISABLED</literal> only at server startup. If + <literal>event_scheduler</literal> is <literal>ON</literal> or + <literal>OFF</literal>, you cannot set it to + <literal>DISABLED</literal> at runtime. Also, if the Event + Scheduler is set to <literal>DISABLED</literal> at startup, you + cannot change the value of <literal>event_scheduler</literal> at + runtime. </para> </important> @@ -415,11 +420,11 @@ <para> To enable the Event Scheduler, restart the server without the - <option>--event-scheduler=<replaceable>DISABLED</replaceable></option> - command line option, or after removing or commenting out the line - containing <literal>event_scheduler=DISABLED</literal> in the - server configuration file, as appropriate. Alternatively, you can - use <literal>ON</literal> (or <literal>1</literal>) or + <option>--event-scheduler=DISABLED</option> command-line option, + or after removing or commenting out the line containing + <literal>event_scheduler=DISABLED</literal> in the server + configuration file, as appropriate. Alternatively, you can use + <literal>ON</literal> (or <literal>1</literal>) or <literal>OFF</literal> (or <literal>0</literal>) in place of the <literal>DISABLED</literal> value when starting the server. </para> @@ -559,7 +564,7 @@ <para> An event can be deleted by any user having the <literal>EVENT</literal> privilege for the database on which - the event is defined. Prior to MySQL 5.12, a user other than + the event is defined. Prior to MySQL 5.1.12, a user other than the definer required privileges on the <literal>mysql.event</literal> table. See <xref linkend="events-privileges"/>. @@ -683,6 +688,32 @@ </programlisting> <para> + It is possible to change multiple characteristics of an event in + a single statement. This example changes the SQL statement + executed by <literal>myevent</literal> to one that deletes all + records from <literal>mytable</literal>; it also changes the + schedule for the event such that it executes once, one day after + this <literal>ALTER EVENT</literal> statement is run. + </para> + +<programlisting> +ALTER TABLE myevent + ON SCHEDULE + AT CURRENT_TIMESTAMP + INTERVAL 1 DAY + DO + TRUNCATE TABLE myschema.mytable; +</programlisting> + + <para> + It is necessary to include only those options in an + <literal>ALTER EVENT</literal> statement which correspond to + characteristics that you actually wish to change; options which + are omitted retain their existing values. This includes any + default values for <literal>CREATE EVENT</literal> such as + <literal>ENABLE</literal>. + </para> + + <para> To disable <literal>myevent</literal>, use this <literal>ALTER EVENT</literal> statement: </para> @@ -716,25 +747,10 @@ </para> <para> - It is possible to change multiple characteristics of an event in - a single statement. This example changes the SQL statement - executed by <literal>myevent</literal> to one that deletes all - records from <literal>mytable</literal>; it also changes the - schedule for the event such that it executes once, one day after - this <literal>ALTER EVENT</literal> statement is run. - </para> - -<programlisting> -ALTER TABLE myevent - ON SCHEDULE - AT CURRENT_TIMESTAMP + INTERVAL 1 DAY - DO - TRUNCATE TABLE myschema.mytable; -</programlisting> - - <para> To rename an event, use the <literal>ALTER EVENT</literal> - statement's <literal>RENAME TO</literal> clause, as shown here: + statement's <literal>RENAME TO</literal> clause. This statement + renames the event <literal>myevent</literal> to + <literal>yourevent</literal>: </para> <programlisting> @@ -743,20 +759,9 @@ </programlisting> <para> - The previous statement renames the event - <literal>myevent</literal> to <literal>yourevent</literal>. - - <note> - <para> - There is no <literal>RENAME EVENT</literal> statement. - </para> - </note> - </para> - - <para> You can also move an event to a different database using <literal>ALTER EVENT ... RENAME TO ...</literal> and - <literal><replaceable>db_name.table_name</replaceable></literal> + <literal><replaceable>db_name.event_name</replaceable></literal> notation, as shown here: </para> @@ -766,11 +771,17 @@ </programlisting> <para> - In order to execute the previous statement, the user executing - it must have the <literal>EVENT</literal> privilege on both the + To execute the previous statement, the user executing it must + have the <literal>EVENT</literal> privilege on both the <literal>olddb</literal> and <literal>newdb</literal> databases. </para> + <note> + <para> + There is no <literal>RENAME EVENT</literal> statement. + </para> + </note> + <para> Beginning with MySQL 5.1.18, a third value may also appear in place of <literal>ENABLED</literal> or @@ -785,15 +796,6 @@ information. </para> - <para> - It is necessary to include only those options in an - <literal>ALTER EVENT</literal> statement which correspond to - characteristics that you actually wish to change; options which - are omitted retain their existing values. This includes any - default values for <literal>CREATE EVENT</literal> such as - <literal>ENABLE</literal>. - </para> - </section> <section id="create-event"> @@ -837,10 +839,10 @@ DO <replaceable>sql_statement</replaceable>; <replaceable>schedule</replaceable>: - AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] + AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] ... | EVERY <replaceable>interval</replaceable> - [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] - [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] + [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] + [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] <replaceable>interval</replaceable>: <replaceable>quantity</replaceable> {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE | @@ -862,12 +864,8 @@ <para> The keywords <literal>CREATE EVENT</literal> plus an event name, which uniquely identifies the event in the current - schema. - </para> - - <para> - (Prior to MySQL 5.1.12, the event name needed to be unique - only among events created by the same user on a given + schema. (Prior to MySQL 5.1.12, the event name needed to be + unique only among events created by the same user on a given database.) </para> </listitem> @@ -922,8 +920,8 @@ <para> If no schema is indicated as part of - <replaceable>event_name</replaceable>, then the default - (current) schema is assumed. + <replaceable>event_name</replaceable>, the default (current) + schema is assumed. </para> <remark role="help-description-end"/> @@ -946,8 +944,9 @@ format (the same format used in the <literal>GRANT</literal> statement). The <replaceable>user_name</replaceable> and <replaceable>host_name</replaceable> values both are required. - <function role="sql">CURRENT_USER</function> also can be given - as <function role="sql">CURRENT_USER()</function>. The default + The definer can also be given as + <function role="sql">CURRENT_USER</function> or + <function role="sql">CURRENT_USER()</function>. The default <literal>DEFINER</literal> value is the user who executes the <literal>CREATE EVENT</literal> statement. (This is the same as <literal>DEFINER = CURRENT_USER</literal>.) @@ -961,9 +960,9 @@ </para> <para> - <literal>IF NOT EXISTS</literal> functions in the same fashion - with <literal>CREATE EVENT</literal> as it does when used with a - <literal>CREATE TABLE</literal> statement; if an event named + <literal>IF NOT EXISTS</literal> has the same meaning for + <literal>CREATE EVENT</literal> as for <literal>CREATE + TABLE</literal>: If an event named <replaceable>event_name</replaceable> already exists in the same schema, no action is taken, and no error results. (However, a warning is generated in such cases.) @@ -982,11 +981,11 @@ <para> <literal>AT <replaceable>timestamp</replaceable></literal> is used for a one-time event. It specifies that the event - executes one time only at the date and time, given as the + executes one time only at the date and time given by <replaceable>timestamp</replaceable>, which must include both the date and time, or must be an expression that - resolves to a datetime value. You may use a value which is - of either the <literal>DATETIME</literal> or + resolves to a datetime value. You may use a value of either + the <literal>DATETIME</literal> or <literal>TIMESTAMP</literal> type for this purpose. If the date is in the past, a warning occurs, as shown here: </para> @@ -1028,11 +1027,10 @@ </para> <para> - In order to create an event which occurs at some point in - the future relative to the current date and time — - such as that expressed by the phrase <quote>three weeks from - now</quote> — you can use the optional clause - <literal>+ INTERVAL + To create an event which occurs at some point in the future + relative to the current date and time — such as that + expressed by the phrase <quote>three weeks from now</quote> + — you can use the optional clause <literal>+ INTERVAL <replaceable>interval</replaceable></literal>. The <replaceable>interval</replaceable> portion consists of two parts, a quantity and a unit of time, and follows the same @@ -1040,14 +1038,13 @@ <function role="sql">DATE_ADD()</function> function (see <xref linkend="date-and-time-functions"/>. The units keywords are also the same, except that you cannot use any - units involving microseconds when defining an event. + units involving microseconds when defining an event. With + some interval types, complex time units may be used. For + example, <quote>two minutes and ten seconds</quote> can be + expressed as <literal>+ INTERVAL '2:10' + MINUTE_SECOND</literal>. </para> - <remark role="note"> - The following does not produce a syntax error, so if it is - wrong, then it should do so. - </remark> - <para> You can also combine intervals. For example, <literal>AT CURRENT_TIMESTAMP + INTERVAL 3 WEEK + INTERVAL 2 @@ -1059,8 +1056,8 @@ <listitem> <para> - For actions which are to be repeated at a regular interval, - you can use an <literal>EVERY</literal> clause. The + To repeat actions at a regular interval, use an + <literal>EVERY</literal> clause. The <literal>EVERY</literal> keyword is followed by an <replaceable>interval</replaceable> as described in the previous dicussion of the <literal>AT</literal> keyword. @@ -1071,12 +1068,10 @@ </para> <para> - It is not possible to combine <literal>+ INTERVAL</literal> - clauses in a single <literal>EVERY</literal> clause; - however, you can use the same complex time units allowed in - a <literal>+ INTERVAL</literal>. For example, <quote>every - two minutes and ten seconds</quote> can be expressed as - <literal>EVERY '2:10' MINUTE_SECOND</literal>. + Although <literal>+ INTERVAL</literal> clauses are not + allowed in an <literal>EVERY</literal> clause, you can use + the same complex time units allowed in a <literal>+ + INTERVAL</literal>. </para> <para> @@ -1247,29 +1242,29 @@ <note> <para> - The <literal>SHOW</literal> statement and - <literal>SELECT</literal> statements that merely return a - result set have no effect when used in an event; the output - from these is not sent to the MySQL Monitor, nor is it stored - anywhere. However, you can use statements such as - <literal>SELECT INTO</literal> and <literal>INSERT ... - SELECT</literal> that store a result. (See the next example in - this section for an instance of the latter.) + Statements such as <literal>SELECT</literal> or + <literal>SHOW</literal> that merely return a result set have + no effect when used in an event; the output from these is not + sent to the MySQL Monitor, nor is it stored anywhere. However, + you can use statements such as <literal>SELECT ... + INTO</literal> and <literal>INSERT INTO ... SELECT</literal> + that store a result. (See the next example in this section for + an instance of the latter.) </para> </note> <para> - Any reference in the <literal>DO</literal> clause to a table in - other than the same database schema to which the event belongs - must be qualified with the name of the schema in which the table - occurs. (In MySQL 5.1.6, all tables referenced in event - <literal>DO</literal> clauses had to include a reference to the - database.) + The schema to which an event belongs is the default schema for + table references in the <literal>DO</literal> clause. Any + references to tables in other schemas must be qualified with the + proper schema name. (In MySQL 5.1.6, all tables referenced in + event <literal>DO</literal> clauses had to include a reference + to the schema.) </para> <para> - As with stored routines, you can use multiple statements in the - <literal>DO</literal> clause by bracketing them with the + As with stored routines, you can use compound-statement syntax + in the <literal>DO</literal> clause by using the <literal>BEGIN</literal> and <literal>END</literal> keywords, as shown here: </para> @@ -1293,7 +1288,7 @@ </programlisting> <para> - Note the use of the <literal>DELIMITER</literal> statement to + Note the use of the <literal>DELIMITER</literal> command to change the statement delimiter, as with stored routines. See <xref linkend="create-procedure"/>. </para> @@ -1566,8 +1561,8 @@ <para> To enable or disable the execution of scheduled events, it is necessary to set the value of the global - <literal>event_scheduler</literal> variable. This requires the - <literal>SUPER</literal> privilege. + <literal>event_scheduler</literal> system variable. This requires + the <literal>SUPER</literal> privilege. </para> <para> Modified: trunk/refman-5.1/events.xml =================================================================== --- trunk/refman-5.1/events.xml 2008-05-08 15:40:57 UTC (rev 10691) +++ trunk/refman-5.1/events.xml 2008-05-08 16:55:11 UTC (rev 10692) Changed blocks: 23, Lines Added: 109, Lines Deleted: 111; 17548 bytes @@ -68,8 +68,7 @@ <listitem> <para> <xref linkend="events-limitations-restrictions"/>, describes the - restrictions and limitations of MySQL's Event Scheduler - implementation. + restrictions and limitations on the use of events. </para> </listitem> @@ -214,8 +213,9 @@ thread</firstterm>; when we refer to the Event Scheduler, we actually refer to this thread. When running, the event scheduler thread and its current state can be seen by users having the - <literal>SUPER</literal> privilege in the output of <literal>SHOW - PROCESSLIST</literal>, as shown in the discussion that follows. + <literal>PROCESS</literal> privilege in the output of + <literal>SHOW PROCESSLIST</literal>, as shown in the discussion + that follows. </para> <indexterm> @@ -231,6 +231,9 @@ <para id="events-event-scheduler-option"> The global variable <literal>event_scheduler</literal> determines whether the Event Scheduler is enabled and running on the server. + affect event scheduling as described here: The global + <literal>event_scheduler</literal> system variable determines + whether the Event Scheduler is enabled and running on the server. Beginning with MySQL 5.1.12, it has one of these 3 values, which affect event scheduling as described here: </para> @@ -308,15 +311,17 @@ Scheduler non-operational. When the Event Scheduler is <literal>DISABLED</literal>, the event scheduler thread does not run (and so does not appear in the output of <literal>SHOW - PROCESSLIST</literal>). + PROCESSLIST</literal>). In addition, the Event Scheduler state + cannot be changed at runtime. </para> </listitem> </itemizedlist> <para> - When the server is running<literal>event_scheduler</literal> can - be toggled between <literal>ON</literal> and + If the Event Scheduler status has not been set to + <literal>DISABLED</literal>, <literal>event_scheduler</literal> + can be toggled between <literal>ON</literal> and <literal>OFF</literal> (using <literal>SET</literal>). It is also possible to use <literal>0</literal> for <literal>OFF</literal>, and <literal>1</literal> for <literal>ON</literal> when setting @@ -370,14 +375,14 @@ <important> <para> - It is not possible to enable or disable the Event Scheduler when - the server is running. That is, you can change the value of - <literal>event_scheduler</literal> to - <literal>DISABLED</literal> — or from - <literal>DISABLED</literal> to one of the other permitted values - for this option — only when the server is stopped. - Attempting to do so when the server is running fails with an - error. + It is possible to set the Event Scheduler to + <literal>DISABLED</literal> only at server startup. If + <literal>event_scheduler</literal> is <literal>ON</literal> or + <literal>OFF</literal>, you cannot set it to + <literal>DISABLED</literal> at runtime. Also, if the Event + Scheduler is set to <literal>DISABLED</literal> at startup, you + cannot change the value of <literal>event_scheduler</literal> at + runtime. </para> </important> @@ -415,11 +420,11 @@ <para> To enable the Event Scheduler, restart the server without the - <option>--event-scheduler=<replaceable>DISABLED</replaceable></option> - command line option, or after removing or commenting out the line - containing <literal>event_scheduler=DISABLED</literal> in the - server configuration file, as appropriate. Alternatively, you can - use <literal>ON</literal> (or <literal>1</literal>) or + <option>--event-scheduler=DISABLED</option> command-line option, + or after removing or commenting out the line containing + <literal>event_scheduler=DISABLED</literal> in the server + configuration file, as appropriate. Alternatively, you can use + <literal>ON</literal> (or <literal>1</literal>) or <literal>OFF</literal> (or <literal>0</literal>) in place of the <literal>DISABLED</literal> value when starting the server. </para> @@ -559,7 +564,7 @@ <para> An event can be deleted by any user having the <literal>EVENT</literal> privilege for the database on which - the event is defined. Prior to MySQL 5.12, a user other than + the event is defined. Prior to MySQL 5.1.12, a user other than the definer required privileges on the <literal>mysql.event</literal> table. See <xref linkend="events-privileges"/>. @@ -683,6 +688,32 @@ </programlisting> <para> + It is possible to change multiple characteristics of an event in + a single statement. This example changes the SQL statement + executed by <literal>myevent</literal> to one that deletes all + records from <literal>mytable</literal>; it also changes the + schedule for the event such that it executes once, one day after + this <literal>ALTER EVENT</literal> statement is run. + </para> + +<programlisting> +ALTER TABLE myevent + ON SCHEDULE + AT CURRENT_TIMESTAMP + INTERVAL 1 DAY + DO + TRUNCATE TABLE myschema.mytable; +</programlisting> + + <para> + It is necessary to include only those options in an + <literal>ALTER EVENT</literal> statement which correspond to + characteristics that you actually wish to change; options which + are omitted retain their existing values. This includes any + default values for <literal>CREATE EVENT</literal> such as + <literal>ENABLE</literal>. + </para> + + <para> To disable <literal>myevent</literal>, use this <literal>ALTER EVENT</literal> statement: </para> @@ -716,25 +747,10 @@ </para> <para> - It is possible to change multiple characteristics of an event in - a single statement. This example changes the SQL statement - executed by <literal>myevent</literal> to one that deletes all - records from <literal>mytable</literal>; it also changes the - schedule for the event such that it executes once, one day after - this <literal>ALTER EVENT</literal> statement is run. - </para> - -<programlisting> -ALTER TABLE myevent - ON SCHEDULE - AT CURRENT_TIMESTAMP + INTERVAL 1 DAY - DO - TRUNCATE TABLE myschema.mytable; -</programlisting> - - <para> To rename an event, use the <literal>ALTER EVENT</literal> - statement's <literal>RENAME TO</literal> clause, as shown here: + statement's <literal>RENAME TO</literal> clause. This statement + renames the event <literal>myevent</literal> to + <literal>yourevent</literal>: </para> <programlisting> @@ -743,20 +759,9 @@ </programlisting> <para> - The previous statement renames the event - <literal>myevent</literal> to <literal>yourevent</literal>. - - <note> - <para> - There is no <literal>RENAME EVENT</literal> statement. - </para> - </note> - </para> - - <para> You can also move an event to a different database using <literal>ALTER EVENT ... RENAME TO ...</literal> and - <literal><replaceable>db_name.table_name</replaceable></literal> + <literal><replaceable>db_name.event_name</replaceable></literal> notation, as shown here: </para> @@ -766,11 +771,17 @@ </programlisting> <para> - In order to execute the previous statement, the user executing - it must have the <literal>EVENT</literal> privilege on both the + To execute the previous statement, the user executing it must + have the <literal>EVENT</literal> privilege on both the <literal>olddb</literal> and <literal>newdb</literal> databases. </para> + <note> + <para> + There is no <literal>RENAME EVENT</literal> statement. + </para> + </note> + <para> Beginning with MySQL 5.1.18, a third value may also appear in place of <literal>ENABLED</literal> or @@ -785,15 +796,6 @@ information. </para> - <para> - It is necessary to include only those options in an - <literal>ALTER EVENT</literal> statement which correspond to - characteristics that you actually wish to change; options which - are omitted retain their existing values. This includes any - default values for <literal>CREATE EVENT</literal> such as - <literal>ENABLE</literal>. - </para> - </section> <section id="create-event"> @@ -837,10 +839,10 @@ DO <replaceable>sql_statement</replaceable>; <replaceable>schedule</replaceable>: - AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] + AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] ... | EVERY <replaceable>interval</replaceable> - [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] - [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] + [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] + [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] <replaceable>interval</replaceable>: <replaceable>quantity</replaceable> {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE | @@ -918,8 +920,8 @@ <para> If no schema is indicated as part of - <replaceable>event_name</replaceable>, then the default - (current) schema is assumed. + <replaceable>event_name</replaceable>, the default (current) + schema is assumed. </para> <remark role="help-description-end"/> @@ -958,9 +960,9 @@ </para> <para> - <literal>IF NOT EXISTS</literal> functions in the same fashion - with <literal>CREATE EVENT</literal> as it does when used with a - <literal>CREATE TABLE</literal> statement; if an event named + <literal>IF NOT EXISTS</literal> has the same meaning for + <literal>CREATE EVENT</literal> as for <literal>CREATE + TABLE</literal>: If an event named <replaceable>event_name</replaceable> already exists in the same schema, no action is taken, and no error results. (However, a warning is generated in such cases.) @@ -979,11 +981,11 @@ <para> <literal>AT <replaceable>timestamp</replaceable></literal> is used for a one-time event. It specifies that the event - executes one time only at the date and time, given as the + executes one time only at the date and time given by <replaceable>timestamp</replaceable>, which must include both the date and time, or must be an expression that - resolves to a datetime value. You may use a value which is - of either the <literal>DATETIME</literal> or + resolves to a datetime value. You may use a value of either + the <literal>DATETIME</literal> or <literal>TIMESTAMP</literal> type for this purpose. If the date is in the past, a warning occurs, as shown here: </para> @@ -1025,11 +1027,10 @@ </para> <para> - In order to create an event which occurs at some point in - the future relative to the current date and time — - such as that expressed by the phrase <quote>three weeks from - now</quote> — you can use the optional clause - <literal>+ INTERVAL + To create an event which occurs at some point in the future + relative to the current date and time — such as that + expressed by the phrase <quote>three weeks from now</quote> + — you can use the optional clause <literal>+ INTERVAL <replaceable>interval</replaceable></literal>. The <replaceable>interval</replaceable> portion consists of two parts, a quantity and a unit of time, and follows the same @@ -1037,14 +1038,13 @@ <function role="sql">DATE_ADD()</function> function (see <xref linkend="date-and-time-functions"/>. The units keywords are also the same, except that you cannot use any - units involving microseconds when defining an event. + units involving microseconds when defining an event. With + some interval types, complex time units may be used. For + example, <quote>two minutes and ten seconds</quote> can be + expressed as <literal>+ INTERVAL '2:10' + MINUTE_SECOND</literal>. </para> - <remark role="note"> - The following does not produce a syntax error, so if it is - wrong, then it should do so. - </remark> - <para> You can also combine intervals. For example, <literal>AT CURRENT_TIMESTAMP + INTERVAL 3 WEEK + INTERVAL 2 @@ -1056,8 +1056,8 @@ <listitem> <para> - For actions which are to be repeated at a regular interval, - you can use an <literal>EVERY</literal> clause. The + To repeat actions at a regular interval, use an + <literal>EVERY</literal> clause. The <literal>EVERY</literal> keyword is followed by an <replaceable>interval</replaceable> as described in the previous dicussion of the <literal>AT</literal> keyword. @@ -1068,12 +1068,10 @@ </para> <para> - It is not possible to combine <literal>+ INTERVAL</literal> - clauses in a single <literal>EVERY</literal> clause; - however, you can use the same complex time units allowed in - a <literal>+ INTERVAL</literal>. For example, <quote>every - two minutes and ten seconds</quote> can be expressed as - <literal>EVERY '2:10' MINUTE_SECOND</literal>. + Although <literal>+ INTERVAL</literal> clauses are not + allowed in an <literal>EVERY</literal> clause, you can use + the same complex time units allowed in a <literal>+ + INTERVAL</literal>. </para> <para> @@ -1244,29 +1242,29 @@ <note> <para> - The <literal>SHOW</literal> statement and - <literal>SELECT</literal> statements that merely return a - result set have no effect when used in an event; the output - from these is not sent to the MySQL Monitor, nor is it stored - anywhere. However, you can use statements such as - <literal>SELECT INTO</literal> and <literal>INSERT ... - SELECT</literal> that store a result. (See the next example in - this section for an instance of the latter.) + Statements such as <literal>SELECT</literal> or + <literal>SHOW</literal> that merely return a result set have + no effect when used in an event; the output from these is not + sent to the MySQL Monitor, nor is it stored anywhere. However, + you can use statements such as <literal>SELECT ... + INTO</literal> and <literal>INSERT INTO ... SELECT</literal> + that store a result. (See the next example in this section for + an instance of the latter.) </para> </note> <para> - Any reference in the <literal>DO</literal> clause to a table in - other than the same database schema to which the event belongs - must be qualified with the name of the schema in which the table - occurs. (In MySQL 5.1.6, all tables referenced in event - <literal>DO</literal> clauses had to include a reference to the - database.) + The schema to which an event belongs is the default schema for + table references in the <literal>DO</literal> clause. Any + references to tables in other schemas must be qualified with the + proper schema name. (In MySQL 5.1.6, all tables referenced in + event <literal>DO</literal> clauses had to include a reference + to the schema.) </para> <para> - As with stored routines, you can use multiple statements in the - <literal>DO</literal> clause by bracketing them with the + As with stored routines, you can use compound-statement syntax + in the <literal>DO</literal> clause by using the <literal>BEGIN</literal> and <literal>END</literal> keywords, as shown here: </para> @@ -1290,7 +1288,7 @@ </programlisting> <para> - Note the use of the <literal>DELIMITER</literal> statement to + Note the use of the <literal>DELIMITER</literal> command to change the statement delimiter, as with stored routines. See <xref linkend="create-procedure"/>. </para> @@ -1563,8 +1561,8 @@ <para> To enable or disable the execution of scheduled events, it is necessary to set the value of the global - <literal>event_scheduler</literal> variable. This requires the - <literal>SUPER</literal> privilege. + <literal>event_scheduler</literal> system variable. This requires + the <literal>SUPER</literal> privilege. </para> <para> Modified: trunk/refman-6.0/events.xml =================================================================== --- trunk/refman-6.0/events.xml 2008-05-08 15:40:57 UTC (rev 10691) +++ trunk/refman-6.0/events.xml 2008-05-08 16:55:11 UTC (rev 10692) Changed blocks: 22, Lines Added: 107, Lines Deleted: 112; 16917 bytes @@ -68,8 +68,7 @@ <listitem> <para> <xref linkend="events-limitations-restrictions"/>, describes the - restrictions and limitations of MySQL's Event Scheduler - implementation. + restrictions and limitations on the use of events. </para> </listitem> @@ -210,8 +209,9 @@ thread</firstterm>; when we refer to the Event Scheduler, we actually refer to this thread. When running, the event scheduler thread and its current state can be seen by users having the - <literal>SUPER</literal> privilege in the output of <literal>SHOW - PROCESSLIST</literal>, as shown in the discussion that follows. + <literal>PROCESS</literal> privilege in the output of + <literal>SHOW PROCESSLIST</literal>, as shown in the discussion + that follows. </para> <indexterm> @@ -225,10 +225,10 @@ </indexterm> <para id="events-event-scheduler-option"> - The global variable <literal>event_scheduler</literal> determines - whether the Event Scheduler is enabled and running on the server. - In MySQL ¤t-series;, it has one of these 3 values, which - affect event scheduling as described here: + The global <literal>event_scheduler</literal> system variable + determines whether the Event Scheduler is enabled and running on + the server. In MySQL ¤t-series;, it has one of these 3 + values, which affect event scheduling as described here: </para> <itemizedlist> @@ -304,15 +304,17 @@ Scheduler non-operational. When the Event Scheduler is <literal>DISABLED</literal>, the event scheduler thread does not run (and so does not appear in the output of <literal>SHOW - PROCESSLIST</literal>). + PROCESSLIST</literal>). In addition, the Event Scheduler state + cannot be changed at runtime. </para> </listitem> </itemizedlist> <para> - When the server is running<literal>event_scheduler</literal> can - be toggled between <literal>ON</literal> and + If the Event Scheduler status has not been set to + <literal>DISABLED</literal>, <literal>event_scheduler</literal> + can be toggled between <literal>ON</literal> and <literal>OFF</literal> (using <literal>SET</literal>). It is also possible to use <literal>0</literal> for <literal>OFF</literal>, and <literal>1</literal> for <literal>ON</literal> when setting @@ -366,14 +368,14 @@ <important> <para> - It is not possible to enable or disable the Event Scheduler when - the server is running. That is, you can change the value of - <literal>event_scheduler</literal> to - <literal>DISABLED</literal> — or from - <literal>DISABLED</literal> to one of the other permitted values - for this option — only when the server is stopped. - Attempting to do so when the server is running fails with an - error. + It is possible to set the Event Scheduler to + <literal>DISABLED</literal> only at server startup. If + <literal>event_scheduler</literal> is <literal>ON</literal> or + <literal>OFF</literal>, you cannot set it to + <literal>DISABLED</literal> at runtime. Also, if the Event + Scheduler is set to <literal>DISABLED</literal> at startup, you + cannot change the value of <literal>event_scheduler</literal> at + runtime. </para> </important> @@ -411,11 +413,11 @@ <para> To enable the Event Scheduler, restart the server without the - <option>--event-scheduler=<replaceable>DISABLED</replaceable></option> - command line option, or after removing or commenting out the line - containing <literal>event_scheduler=DISABLED</literal> in the - server configuration file, as appropriate. Alternatively, you can - use <literal>ON</literal> (or <literal>1</literal>) or + <option>--event-scheduler=DISABLED</option> command-line option, + or after removing or commenting out the line containing + <literal>event_scheduler=DISABLED</literal> in the server + configuration file, as appropriate. Alternatively, you can use + <literal>ON</literal> (or <literal>1</literal>) or <literal>OFF</literal> (or <literal>0</literal>) in place of the <literal>DISABLED</literal> value when starting the server. </para> @@ -620,6 +622,32 @@ </programlisting> <para> + It is possible to change multiple characteristics of an event in + a single statement. This example changes the SQL statement + executed by <literal>myevent</literal> to one that deletes all + records from <literal>mytable</literal>; it also changes the + schedule for the event such that it executes once, one day after + this <literal>ALTER EVENT</literal> statement is run. + </para> + +<programlisting> +ALTER TABLE myevent + ON SCHEDULE + AT CURRENT_TIMESTAMP + INTERVAL 1 DAY + DO + TRUNCATE TABLE myschema.mytable; +</programlisting> + + <para> + It is necessary to include only those options in an + <literal>ALTER EVENT</literal> statement which correspond to + characteristics that you actually wish to change; options which + are omitted retain their existing values. This includes any + default values for <literal>CREATE EVENT</literal> such as + <literal>ENABLE</literal>. + </para> + + <para> To disable <literal>myevent</literal>, use this <literal>ALTER EVENT</literal> statement: </para> @@ -653,25 +681,10 @@ </para> <para> - It is possible to change multiple characteristics of an event in - a single statement. This example changes the SQL statement - executed by <literal>myevent</literal> to one that deletes all - records from <literal>mytable</literal>; it also changes the - schedule for the event such that it executes once, one day after - this <literal>ALTER EVENT</literal> statement is run. - </para> - -<programlisting> -ALTER TABLE myevent - ON SCHEDULE - AT CURRENT_TIMESTAMP + INTERVAL 1 DAY - DO - TRUNCATE TABLE myschema.mytable; -</programlisting> - - <para> To rename an event, use the <literal>ALTER EVENT</literal> - statement's <literal>RENAME TO</literal> clause, as shown here: + statement's <literal>RENAME TO</literal> clause. This statement + renames the event <literal>myevent</literal> to + <literal>yourevent</literal>: </para> <programlisting> @@ -680,20 +693,9 @@ </programlisting> <para> - The previous statement renames the event - <literal>myevent</literal> to <literal>yourevent</literal>. - - <note> - <para> - There is no <literal>RENAME EVENT</literal> statement. - </para> - </note> - </para> - - <para> You can also move an event to a different database using <literal>ALTER EVENT ... RENAME TO ...</literal> and - <literal><replaceable>db_name.table_name</replaceable></literal> + <literal><replaceable>db_name.event_name</replaceable></literal> notation, as shown here: </para> @@ -703,11 +705,17 @@ </programlisting> <para> - In order to execute the previous statement, the user executing - it must have the <literal>EVENT</literal> privilege on both the + To execute the previous statement, the user executing it must + have the <literal>EVENT</literal> privilege on both the <literal>olddb</literal> and <literal>newdb</literal> databases. </para> + <note> + <para> + There is no <literal>RENAME EVENT</literal> statement. + </para> + </note> + <para> A third value may also appear in place of <literal>ENABLED</literal> or <literal>DISABLED</literal>; @@ -721,15 +729,6 @@ information. </para> - <para> - It is necessary to include only those options in an - <literal>ALTER EVENT</literal> statement which correspond to - characteristics that you actually wish to change; options which - are omitted retain their existing values. This includes any - default values for <literal>CREATE EVENT</literal> such as - <literal>ENABLE</literal>. - </para> - </section> <section id="create-event"> @@ -773,10 +772,10 @@ DO <replaceable>sql_statement</replaceable>; <replaceable>schedule</replaceable>: - AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] + AT <replaceable>timestamp</replaceable> [+ INTERVAL <replaceable>interval</replaceable>] ... | EVERY <replaceable>interval</replaceable> - [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] - [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval]] + [STARTS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] + [ENDS <replaceable>timestamp</replaceable> [+ INTERVAL interval] ...] <replaceable>interval</replaceable>: <replaceable>quantity</replaceable> {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE | @@ -852,8 +851,8 @@ <para> If no schema is indicated as part of - <replaceable>event_name</replaceable>, then the default - (current) schema is assumed. + <replaceable>event_name</replaceable>, the default (current) + schema is assumed. </para> <remark role="help-description-end"/> @@ -884,9 +883,9 @@ </para> <para> - <literal>IF NOT EXISTS</literal> functions in the same fashion - with <literal>CREATE EVENT</literal> as it does when used with a - <literal>CREATE TABLE</literal> statement; if an event named + <literal>IF NOT EXISTS</literal> has the same meaning for + <literal>CREATE EVENT</literal> as for <literal>CREATE + TABLE</literal>: If an event named <replaceable>event_name</replaceable> already exists in the same schema, no action is taken, and no error results. (However, a warning is generated in such cases.) @@ -905,11 +904,11 @@ <para> <literal>AT <replaceable>timestamp</replaceable></literal> is used for a one-time event. It specifies that the event - executes one time only at the date and time, given as the + executes one time only at the date and time given by <replaceable>timestamp</replaceable>, which must include both the date and time, or must be an expression that - resolves to a datetime value. You may use a value which is - of either the <literal>DATETIME</literal> or + resolves to a datetime value. You may use a value of either + the <literal>DATETIME</literal> or <literal>TIMESTAMP</literal> type for this purpose. If the date is in the past, a warning occurs, as shown here: </para> @@ -951,11 +950,10 @@ </para> <para> - In order to create an event which occurs at some point in - the future relative to the current date and time — - such as that expressed by the phrase <quote>three weeks from - now</quote> — you can use the optional clause - <literal>+ INTERVAL + To create an event which occurs at some point in the future + relative to the current date and time — such as that + expressed by the phrase <quote>three weeks from now</quote> + — you can use the optional clause <literal>+ INTERVAL <replaceable>interval</replaceable></literal>. The <replaceable>interval</replaceable> portion consists of two parts, a quantity and a unit of time, and follows the same @@ -963,14 +961,13 @@ <function role="sql">DATE_ADD()</function> function (see <xref linkend="date-and-time-functions"/>. The units keywords are also the same, except that you cannot use any - units involving microseconds when defining an event. + units involving microseconds when defining an event. With + some interval types, complex time units may be used. For + example, <quote>two minutes and ten seconds</quote> can be + expressed as <literal>+ INTERVAL '2:10' + MINUTE_SECOND</literal>. </para> - <remark role="note"> - The following does not produce a syntax error, so if it is - wrong, then it should do so. - </remark> - <para> You can also combine intervals. For example, <literal>AT CURRENT_TIMESTAMP + INTERVAL 3 WEEK + INTERVAL 2 @@ -982,8 +979,8 @@ <listitem> <para> - For actions which are to be repeated at a regular interval, - you can use an <literal>EVERY</literal> clause. The + To repeat actions at a regular interval, use an + <literal>EVERY</literal> clause. The <literal>EVERY</literal> keyword is followed by an <replaceable>interval</replaceable> as described in the previous dicussion of the <literal>AT</literal> keyword. @@ -994,12 +991,10 @@ </para> <para> - It is not possible to combine <literal>+ INTERVAL</literal> - clauses in a single <literal>EVERY</literal> clause; - however, you can use the same complex time units allowed in - a <literal>+ INTERVAL</literal>. For example, <quote>every - two minutes and ten seconds</quote> can be expressed as - <literal>EVERY '2:10' MINUTE_SECOND</literal>. + Although <literal>+ INTERVAL</literal> clauses are not + allowed in an <literal>EVERY</literal> clause, you can use + the same complex time units allowed in a <literal>+ + INTERVAL</literal>. </para> <para> @@ -1159,27 +1154,27 @@ <note> <para> - The <literal>SHOW</literal> statement and - <literal>SELECT</literal> statements that merely return a - result set have no effect when used in an event; the output - from these is not sent to the MySQL Monitor, nor is it stored - anywhere. However, you can use statements such as - <literal>SELECT INTO</literal> and <literal>INSERT ... - SELECT</literal> that store a result. (See the next example in - this section for an instance of the latter.) + Statements such as <literal>SELECT</literal> or + <literal>SHOW</literal> that merely return a result set have + no effect when used in an event; the output from these is not + sent to the MySQL Monitor, nor is it stored anywhere. However, + you can use statements such as <literal>SELECT ... + INTO</literal> and <literal>INSERT INTO ... SELECT</literal> + that store a result. (See the next example in this section for + an instance of the latter.) </para> </note> <para> - Any reference in the <literal>DO</literal> clause to a table in - other than the same database schema to which the event belongs - must be qualified with the name of the schema in which the table - occurs. + The schema to which an event belongs is the default schema for + table references in the <literal>DO</literal> clause. Any + references to tables in other schemas must be qualified with the + proper schema name. </para> <para> - As with stored routines, you can use multiple statements in the - <literal>DO</literal> clause by bracketing them with the + As with stored routines, you can use compound-statement syntax + in the <literal>DO</literal> clause by using the <literal>BEGIN</literal> and <literal>END</literal> keywords, as shown here: </para> @@ -1203,7 +1198,7 @@ </programlisting> <para> - Note the use of the <literal>DELIMITER</literal> statement to + Note the use of the <literal>DELIMITER</literal> command to change the statement delimiter, as with stored routines. See <xref linkend="create-procedure"/>. </para> @@ -1447,8 +1442,8 @@ <para> To enable or disable the execution of scheduled events, it is necessary to set the value of the global - <literal>event_scheduler</literal> variable. This requires the - <literal>SUPER</literal> privilege. + <literal>event_scheduler</literal> system variable. This requires + the <literal>SUPER</literal> privilege. </para> <para>
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|---|---|---|
| • svn commit - mysqldoc@docsrva: r10692 - in trunk: . it/refman-5.1 pt/refman-5.1 refman-5.1 refman-6.0 | paul | 8 May 2008 |
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