tommyh (12/2/2010)
roger.plowman (12/2/2010)
I had the need for this and used a non-clustered unique filtered index. Simple, efficient, and solves the problem neatly while letting SQL Server enforce it.As to why you'd ever want to, the reason I did it was because a field was optional (filled with "N/A") but if it was filled in it had to be with a unique value. So by indexing everything *except* N/A I could ensure the unique value of all "actual" entries.
Thank God 2008 finally implemented something Access has had since 2003. 🙂
<points a few posts up>
"This feature is present in MS-ACCESS starting from version 1.0 (year 1990)."
Dont know if thats true or not. But i wouldnt be supprised.
/T
Dunno either. But since the feature was critical to the design of something I know used it in Access 2003 I was being conservative. 🙂 I believe Access 97 also had it.
Whatever the case it's about time! (laughing)