Monday, May 20, 2013

Before Triggers in SQL Server

There are lots of questions asking whether there are before triggers in SQL Server. There are nothing called Before Triggers in SQL Server.

What is the requirement for the Before Trigger?

Let us say, you want to verify some values other table before inserting it. In SQL Server, you can use INSTEAD OF TRIGGER.

CREATE TRIGGER tr_data_before ON Table_Data
INSTEAD OF INSERT
AS
BEGIN
SET NOCOUNT ON
IF
EXISTS (SELECT 1 FROM Tablle_Data2)
BEGIN
INSERT INTO
dbo.Table_Data
SELECT *
FROM INSERTED
END
END

However, in Oracle and DB2 there are Before Triggers.

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