Table design with NULL in column

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Table design with NULL in column

H-122523

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June 15, 2005 at 5:33 am

#164937

Hello all,
I have this design:
ID int IDENTITY PRIMARY KEY
Nr int
In the Nr-column I want unique identity numbers, OR NULL-values. How do I need to configure this column to get this done? Putting an index on this column is not enough, as it will not allow me to enter more than one row in which the Nr equals NULL.
tia

Hans

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Phil Parkin SSC Guru Points: 246961 More actions · Answer 1

Check out this link for more info on this:

http://www.sqlservercentral.com/forums/shwmessage.aspx?forumid=9&messageid=157147#bm157159

The absence of evidence is not evidence of absence
- Martin Rees
The absence of consumable DDL, sample data and desired results is, however, evidence of the absence of my response
- Phil Parkin

H-122523 Hall of Fame Points: 3667 More actions · Answer 2

Thank you Old Hand,

the VIEW solution will do just fine; any drawbacks known with this solution (performance or otherwise)?

Hans

Phil Parkin SSC Guru Points: 246961 More actions · Answer 3

I've never used this solution - though I see no reason for any drawbacks - except, perhaps, for the ugly message that could be sent back to client apps - non-technical users might not understand what's happened.

Regards

Phil

The absence of evidence is not evidence of absence
- Martin Rees
The absence of consumable DDL, sample data and desired results is, however, evidence of the absence of my response
- Phil Parkin

H-122523 Hall of Fame Points: 3667 More actions · Answer 4

Ok Phil,

thanks again, I'm definitly going to try the view-solution then.

Admin/Moderator: consider issue closed.

regards,

Hans