A trigger is a block of code that constitutes a set of T-SQL statements that are activated in response to certain actions or conditions.
A trigger can also be interpreted as a special kind of stored procedure that is executed whenever an action,such as data modification,takes place.
A Trigger is fired whenever data in the underlying table is affected by any of the Data Manipulation Language (DML) statements -INSERT,UPDATE,OR DELETE.
Triggers help in maintaining consistent,reliable,and correct data in tables.They enable the performance of complex actions and cascade these actions to other dependent tables.
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