Hi,

Being new to SQL, I need some help with the following situation.

I have a linktable that contains a column called TaskID and one called
RequestID. I would like to check on each insertion that there is not already
a taskID added for the particular RequestID. I.e. it should not be possible
to add that TaskID 2 for RequestID 3 has been completed more than once. I
assume that I need to add a Check constraint to achieve this, but I am not
sure how this statement would look like.

Any help appreciated.

Regards

Niclas

Sounds like you need a UNIQUE constraint.

ALTER TABLE SomeTable ADD CONSTRAINT UQ_xyz UNIQUE (taskid,requestid)

--
David Portas
SQL Server MVP
--

Cheers !

Niclas
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