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assigning unique primary keys which are two foreign keys in an association table

Posted on 2009-04-11
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I have an association table with two foreign keys (e.g. stakeholderID, contactID)  that I would like to express in an er diagram.  The tools I have for drawing the er diagram are ms visio 2007 -- and sql server's diagramming feature through management studio.

also, is there any way to express an alternate key?
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Question by:Paula DiTallo
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Raja Jegan R earned 2000 total points
ID: 24123362
So stakeholderID, contactID forms the primary key of that table and in your ER diagram show both of them as primary keys.
What do you mean by Alternate Key
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Author Comment

by:Paula DiTallo
ID: 24123415
cool. ultimately i did just that--with the 2 foreign keys in the _assoc table.  alternate keys may be more of an ERwin/Oracle partnership. In general an alternate key (read: AK1, AK2, etc.) is a candidate that could be used to retrieve (generally) unique data but isn't the primary key.  I hate to use the ol' warn employee table as an example ... but its helpful in the case -- so, an emplID or socSecNum might be primary keys, but something like a badgeNum would be an alternate key.
 
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Author Closing Comment

by:Paula DiTallo
ID: 31569221
thanks so much for answering...
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