1. Enabling the Event Scheduler

Turn the event scheduler on (requires SUPER or appropriate privileges):

SET GLOBAL event_scheduler = ON;

Verify scheduler status:

SHOW VARIABLES LIKE 'event_scheduler';

Note: To enable the scheduler permanently across server restarts, set event_scheduler=ON in your MySQL configuration (e.g., my.cnf).

2. Creating a One-Time Event

Schedule an event to run once at a specified time:

Syntax:

CREATE EVENT event_name
ON SCHEDULE AT timestamp
DO
  -- statement(s) to run;

Example (runs once one hour from now):

CREATE EVENT delete_old_logs
ON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 1 HOUR
DO
  DELETE FROM logs WHERE log_time < NOW() - INTERVAL 30 DAY;

3. Creating a Recurring Event

Schedule an event to run repeatedly at fixed intervals:

Syntax:

CREATE EVENT event_name
ON SCHEDULE EVERY interval
DO
  -- statement(s) to run;

Example (daily cleanup):

CREATE EVENT daily_cleanup
ON SCHEDULE EVERY 1 DAY
DO
  DELETE FROM sessions WHERE last_active < NOW() - INTERVAL 1 DAY;

4. Modifying an Event

Change an event’s schedule or body with ALTER EVENT:

Syntax:

ALTER EVENT event_name
ON SCHEDULE ... 
[DO ...];

Example (change schedule):

ALTER EVENT daily_cleanup
ON SCHEDULE EVERY 1 WEEK;

5. Dropping an Event

Remove an event permanently:

Syntax:

DROP EVENT event_name;

Example:

DROP EVENT delete_old_logs;

6. Viewing Events

To list all events in the current database:

SHOW EVENTS;

To view the full definition (SQL) of a specific event:

SHOW CREATE EVENT event_name;

Example:

SHOW CREATE EVENT daily_cleanup;

Notes & Tips

• You need the EVENT privilege to create, alter, or drop events in a given schema.
• Events execute with the privileges of their DEFINER account by default—be mindful of security.
• Event status can be ENABLED or DISABLED. Use ALTER EVENT ... ENABLE|DISABLE to change it.
• For persistent scheduling across restarts, set event_scheduler=ON in the server configuration file.