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Showing posts from February 19, 2012

How many types of triggers are there in SQL

There are mainily 3 types of triggers DML trigger Instead of trigger written on only view System trigger DML trigger written on table that gets fired on dml events like insert or delete or update operation that trigger may fire  After DML event  Before DML event these are timings for trigger firing Instead of trigger written only on view that view is not modifiable that also gets fired when DML event occurs System trigger gets fired on system event like before log off or after log on or before shutdown this trigger  may be written on   Database level   Schema level  --------------------------------------------------------------------------------------------------------- OR you can see as follows --------------------------------------------------------------------------------------------------------- Based on timing: 1. Before 2. After 3. Instead of Based on Event: 1. DDL (Insert, update, delete ) 2. DML ( Create, alter, analyze, comment ) 3