> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/server-usage/triggers-events/event-scheduler/events.md). # Events Overview [Events](/docs/server/server-usage/triggers-events.md) are named database objects containing SQL statements that are to be executed at a later stage, either once off, or at regular intervals. They function very similarly to the Windows Task Scheduler or Unix cron jobs. Creating, modifying or deleting events requires the [EVENT privilege](/docs/server/reference/sql-statements/account-management-sql-statements/grant.md#database-privileges). ## Creating Events Events are created with the [CREATE EVENT](/docs/server/reference/sql-statements/data-definition/create/create-event.md) statement. ### Example ```sql CREATE EVENT test_event ON SCHEDULE EVERY 1 MINUTE DO UPDATE test.t1 SET a = a + 1; ``` ## Executing Events Events are only executed if the event scheduler is running. This is determined by the value of the [event\_scheduler](/docs/server/server-management/variables-and-modes/server-system-variables.md#event_scheduler) system variable, which needs to be set to `On` for the event scheduler to be running. You can check if the Event scheduler is running with: ```sql SHOW PROCESSLIST; +----+-----------------+-----------+------+---------+------+-----------------------------+------------------+----------+ | Id | User | Host | db | Command | Time | State | Info | Progress | +----+-----------------+-----------+------+---------+------+-----------------------------+------------------+----------+ | 40 | root | localhost | test | Sleep | 4687 | | NULL | 0.000 | | 41 | root | localhost | test | Query | 0 | init | SHOW PROCESSLIST | 0.000 | | 42 | event_scheduler | localhost | NULL | Daemon | 30 | Waiting for next activation | NULL | 0.000 | +----+-----------------+-----------+------+---------+------+-----------------------------+------------------+----------+ ``` If the event scheduler is not running and `event_scheduler` has been set to `OFF`, use: ```sql SET GLOBAL event_scheduler = ON; ``` to activate it. If `event_scheduler` has been set to `Disabled`, you cannot change the value at runtime. Changing the value of the `event_scheduler` variable requires the SUPER privilege. Since [MariaDB 10.0.22](/docs/release-notes/community-server/old-releases/10.0/10.0.22.md), setting the [event\_scheduler](/docs/server/server-management/variables-and-modes/server-system-variables.md#event_scheduler) system variable will also try to reload the [mysql.event table](/docs/server/reference/system-tables/the-mysql-database-tables/mysql-event-table.md) if it was not properly loaded at startup. ## Viewing Current Events A list of current events can be obtained with the [SHOW EVENTS](/docs/server/reference/sql-statements/administrative-sql-statements/show/show-events.md) statement. This only shows the event name and interval - the full event details, including the SQL, can be seen by querying the [Information Schema EVENTS table](/docs/server/reference/system-tables/information-schema/information-schema-tables/information-schema-events-table.md), or with [SHOW CREATE EVENT](/docs/server/reference/sql-statements/administrative-sql-statements/show/show-create-event.md). If an event is currently being executed, it can be seen by querying the [Information Schema PROCESSLIST table](/docs/server/reference/system-tables/information-schema/information-schema-tables/information-schema-processlist-table.md), or with the [SHOW PROCESSLIST](/docs/server/reference/sql-statements/administrative-sql-statements/show/show-processlist.md) statement. ### Example ```sql SHOW EVENTS\G; *************************** 1. row *************************** Db: test Name: test_event Definer: root@localhost Time zone: SYSTEM Type: RECURRING Execute at: NULL Interval value: 1 Interval field: MINUTE Starts: 2013-05-20 13:46:56 Ends: NULL Status: ENABLED Originator: 1 character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` ``` SHOW CREATE EVENT test_event\G *************************** 1. row *************************** Event: test_event sql_mode: time_zone: SYSTEM Create Event: CREATE DEFINER=`root`@`localhost` EVENT `test_event` ON SCHEDULE EVERY 1 MINUTE STARTS '2013-05-20 13:46:56' ON COMPLETION NOT PRESERVE ENABLE DO UPDATE test.t1 SET a = a + 1 character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` ## Altering Events An event can be changed with the [ALTER EVENT](/docs/server/server-usage/triggers-events/event-scheduler/alter-event.md) statement. ### Example ```sql ALTER EVENT test_event ON SCHEDULE EVERY '2:3' DAY_HOUR; ``` ## Dropping Events Events are dropped with the [DROP EVENT](/docs/server/reference/sql-statements/data-definition/drop/drop-event.md) statement. Events are also automatically dropped once they have run for the final time according to their schedule, unless the ON COMPLETION PRESERVE clause has been specified. ### Example ```sql DROP EVENT test_event; Query OK, 0 rows affected (0.00 sec) ``` ## See Also * [CREATE EVENT](/docs/server/reference/sql-statements/data-definition/create/create-event.md) * [SHOW CREATE EVENT](/docs/server/reference/sql-statements/administrative-sql-statements/show/show-create-event.md) * [ALTER EVENT](/docs/server/server-usage/triggers-events/event-scheduler/alter-event.md) * [DROP EVENT](/docs/server/reference/sql-statements/data-definition/drop/drop-event.md) * [Event Limitations](/docs/server/server-usage/triggers-events/event-scheduler/event-limitations.md) * [Automating MariaDB Tasks with Events](/docs/server/server-management/automated-mariadb-deployment-and-administration/automating-mariadb-tasks-with-events.md) *This page is licensed: CC BY-SA / Gnu FDL* {% @marketo/form formId="4316" %}