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JimL
SQL Slinging Yak Ranger
1537 Posts |
 Posted - 2010-05-06 : 13:41:58
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| Is it possible to create a table constraint that would allow Unique or null or 'none'on a columnThe Nulls and the 'none' would need to allow multiples.JimUsers <> Logic |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2010-05-06 : 13:48:50
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| 1. you need to create check constraint for that------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
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dportas
Yak Posting Veteran
53 Posts |
Posted - 2010-05-06 : 14:35:03
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| Normalize it. Move the column into a new table and put the unique constraint on that. For the null or "none" rows you just don't have a row in that new table. That's assuming "none" means the same as null - if it means something else then create a new column for it. |
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tkizer
Almighty SQL Goddess
38200 Posts |
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Unique Constraint with exceptions