MySQL Reference Manual :: 20 Triggers

Rudimentary support for triggers is included beginning with MySQL 5.0.2. A trigger is a named database object that is associated with a table and that activates when a particular event occurs for the table. For example, the following statements set up a table, as well as a trigger for INSERT statements into the table. The trigger sums the values inserted into one of the table's columns:

mysql> CREATE TABLE account (acct_num INT, amount DECIMAL(10,2));
mysql> CREATE TRIGGER ins_sum BEFORE INSERT ON account
    -> FOR EACH ROW SET @sum = @sum + NEW.amount;

This chapter describes the syntax for creating and dropping triggers, and show some examples of how to use them.

Binary logging for triggers is done as described in Section 19.3, “Binary Logging of Stored Routines and Triggers”.