27.4.4 事件元数据
To obtain metadata about events:
-
Query the
EVENTS
table of theINFORMATION_SCHEMA
database. See Section 28.3.14, “The INFORMATION_SCHEMA EVENTS Table”. -
Use the
SHOW CREATE EVENT
statement. See Section 15.7.7.8, “SHOW CREATE EVENT Statement”. -
Use the
SHOW EVENTS
statement. See Section 15.7.7.19, “SHOW EVENTS Statement”.
Event Scheduler Time Representation
Each session in MySQL has a session time zone (STZ). This is the session time_zone
value that is initialized from the server's global time_zone
value when the session begins but may be changed during the session.
The session time zone that is current when a CREATE EVENT
or ALTER EVENT
statement executes is used to interpret times specified in the event definition. This becomes the event time zone (ETZ); that is, the time zone that is used for event scheduling and is in effect within the event as it executes.
For representation of event information in the data dictionary, the execute_at
, starts
, and ends
times are converted to UTC and stored along with the event time zone. This enables event execution to proceed as defined regardless of any subsequent changes to the server time zone or daylight saving time effects. The last_executed
time is also stored in UTC.
Event times can be obtained by selecting from the Information Schema EVENTS
table or from SHOW EVENTS
, but they are reported as ETZ or STZ values. The following table summarizes representation of event times.
Value | EVENTS Table |
SHOW EVENTS |
---|---|---|
Execute at | ETZ | ETZ |
Starts | ETZ | ETZ |
Ends | ETZ | ETZ |
Last executed | ETZ | n/a |
Created | STZ | n/a |
Last altered | STZ | n/a |