1, see MySQL whether to open the event function
View command:
show variables like '%sc%';
Open event_scheduler (temporary open, MySQL service after reboot aging)
SET GLOBAL event_scheduler = ON;
Permanent opening method: my.cnf in the [mysqld] add event_scheduler = on # to restart the service
2, create an event
create event myevent on SCHEDULE every 5 second do delete from Syslog.SystemEvents where ReceivedAt<(CURRENT_TIMESTAMP() + INTERVAL -5 DAY);#删除5天前的数据
Description:
ReceivedAt : Database Syslog.Systemevents time fields in the table
(date,INTERVAL expr type):
DATE : Database current time CURRENT_TIMESTAMP ()
INTERVAL : Keyword (interval)
expr : a specific time interval ( -5 )
type: time units:
MICROSECOND |
Interval Unit: ms |
SECOND |
Spacing unit: seconds |
MINUTE |
Spacing unit: minutes |
HOUR |
Interval Unit: hour |
DAY |
Interval Unit: Day |
WEEK |
Unit interval: week |
MONTH |
Unit interval: Monthly |
QUARTER |
Unit interval: quarter |
YEAR |
Interval Unit: Year |
SECOND_MICROSECOND |
Composite spacer unit: seconds, milliseconds, expr can be used to specify the values of two seconds and milliseconds, respectively |
MINUTE_MICROSECOND |
Complex, Interval Unit: points, ms |
MINUTE_SECOND |
Composite spacer unit: minutes, seconds |
HOUR_MICROSECOND |
Complex, Interval Unit: hours, ms |
HOUR_SECOND |
Complex, Interval Unit: hours, seconds |
HOUR_MINUTE |
Complex, Interval Unit: hours min |
DAY_MICROSECOND |
Composite interval unit: days, ms |
DAY_SECOND |
Composite interval unit: days, seconds |
DAY_MINUTE |
Composite interval unit: day in divided |
DAY_HOUR |
Composite interval unit: days, hours |
YEAR_MONTH |
Complex, unit interval: year, month |
If there is an event, delete, delete the command: drop Event IF EXISTS MyEvent;
3, turn on event
alter event myevent on completion preserve enable;
4、Close the command of the event:alter event myevent on completion preserve disable;