Question

I have inside a stored procedure:

INSERT INTO SitesCategories(SiteID, CategoryID) VALUES(@SITEID, @TempCId);

This insert could throw exceptions because I have this constraint on the table:

  ALTER TABLE dbo.SitesCategories
    ADD CONSTRAINT UniqueSiteCategPair
    UNIQUE (SiteId,CategoryID);

I made this constraint so that I would not have to check when inserting the uniques of the pairs (@SITEID, @TempCId). But I do not want that an SQl exception is thrown when this gets executed inside the stored procedure. How can I “catch” the exception inside the stored procedure and continue operations inside the procedure ?

Answer 1

If you create your UNIQUE CONSTRAINT with the IGNORE_DUP_KEY = ON setting, then duplicates will be silently ignored, e.g. they won’t be inserted into your table, but no exception will be thrown, either:

 ALTER TABLE dbo.SitesCategories
   ADD CONSTRAINT UniqueSiteCategPair
   UNIQUE (SiteId,CategoryID) WITH (IGNORE_DUP_KEY = ON);