Database Trigger - Triggers in PostgreSQL

Triggers in PostgreSQL

PostgreSQL introduced support for triggers in 1997. The following functionality in SQL:2003 was previously not implemented in PostgreSQL:

• SQL allows triggers to fire on updates to specific columns; As of version 9.0 of PostgreSQL this feature is also implemented in PostgreSQL.
• The standard allows the execution of a number of SQL statements other than SELECT, INSERT, UPDATE, such as CREATE TABLE as the triggered action. This can be done through creating a stored procedure or function to call CREATE TABLE.

Synopsis:

SELECT * FROM MY_TABLE; UPDATE MY_TABLE SET A = 5; INSERT INTO MY_TABLE VALUES (3, 'aaa');