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I have a table A with a composite primary key and I have table B where I need to have Table A's colum(s) as foreign key. Do I need to add both column's of Table A in Table B as foreign key?

Please suggest.

David
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DotnetSparrow
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3 Answers3

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Yes you have to add all the columns from table A that defines the primary key to table B.

Mikael Eriksson
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  • +1. If you didn't add all of the columns then you couldn't uniquely identify the rows from table A. – David Apr 13 '11 at 05:58
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Create a surrogate in table A to use as the primary key, and use the composite key columns as a superkey (create a unique, non-null index on the columns). Have the foreign key in table B refer to the surrogate column.

Community
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outis
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Yes you can add both column of table A in table B and can make only One column of table A as foreign Key in table B and also can make both column of table A as foeign key in table B.

Pratiksha Chaudhary
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