MySQL ---- trigger

First, the concept: the need for automatic handling at some of the tables changed. Triggers in MySQL is performed automatically in response to the following statement in a MySQL statement

　　　　(Or a set of statements located between the Begin and END statements)

　　　　  Supported types of statements: INSERT, DELETE, UPDATE

Second, create a trigger, you need to give the following four information

　　1, the only trigger name;

　　2, the trigger is associated table;

　　3, in response to the active trigger should (DELETE, INSERT or the UPDATE);

　　4, when the trigger execution (before or after processing)

three,