Mysql-Trigger Trigger

Trigger (Trigger): A special thing,

Monitor a certain thing operation (Insert/update/delete),

and trigger related actions (Insert/update/delete).

A trigger (trigger) creates 4 features: A watch location (table), a monitoring event (Insert/update/delete), a trigger time (After/before), a trigger event (Insert/update/delete).

Trigger Syntax:

CREATE trigger Add_user_log (trigger name) before (trigger eventafter/before) Update (monitor event) on User_info (monitor table name) for each Rowbegin
#命名变量
Set @user = 0;  INSERT INTO  user_login_log (phone_number,user) VALUES (' 183014138XX ', @user);
#if: else if:
If @user is null then
#触发事件
else if Then
#触发事件

Mysql-Trigger Trigger