I don't know that you need a trigger for this.  Why not just do it with
a unique index constraint?



-----Original Message-----
From: Siva Subramaniyan (IE10)
[mailto:SivaSubramaniyan.Ranganathan@h...]
Sent: Friday, July 27, 2001 5:02 AM
To: sql language
Subject: [sql_language] SQL Triggers

Hi
        I have enforced a constraint in one of the Tables in the
database.
It is something like this.
----------------------------
TABLE1
Secondarykey
Number
----------------------------------
The constraint is SecondaryKey and Number should be unique.The Number
will
be updated by the User.
I would like to use a trigger which should check the constraint on
updating
the data in the table. If there are any errors it should rollback the
transaction. Can anyone tell me how to go about it?

Thanks in Advance
Sivasubramaniyan.