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markman
Starting Member
2 Posts |
 Posted - 2005-02-24 : 19:59:22
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| Hi, I'm fairly new to sql server and I am trying to ensure that two columns have unique values:TestTable:Id bigint (primary)col1Id bigintcol2Id biginton each insert I want to ensure that the COMBINATION of col1Id and col2Id is unique. How do I implement such a thing?Thanks, Mark |
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Ex
Posting Yak Master
166 Posts |
Posted - 2005-02-24 : 20:05:03
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| might be a better way butcan create a unique indexCREATE UNIQUE INDEX indexName ON TestTable (col1Id, col2Id) |
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robvolk
Most Valuable Yak
15732 Posts |
Posted - 2005-02-24 : 20:05:34
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| ALTER TABLE TestTable WITH CHECK ADD CONSTRAINT UNQ_Col1ID_Col2ID UNIQUE (Col1ID, Col2ID) |
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robvolk
Most Valuable Yak
15732 Posts |
Posted - 2005-02-24 : 20:07:15
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| You can use a unique index too, a unique constraint creates a unique index.If both columns must be unique, why not make them the primary key? Then you can drop the ID column. |
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markman
Starting Member
2 Posts |
Posted - 2005-02-24 : 21:18:11
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| thanks for the help, I agree that I should drop my primary key since col1 and col2 effectively establish a primary key but it's easier for me to keep it. I finally was able to add a unique constraint on the two columns and it seems to work. Thanks again.Mark |
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unique constraint on two columns