3 foreign keys in 1 table for 3 1-to-many relations?

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От gvim
Тема 3 foreign keys in 1 table for 3 1-to-many relations?
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Msg-id 5582161F.7070809@gmail.com
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Ответы Re: 3 foreign keys in 1 table for 3 1-to-many relations?
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I have 3 tables A, B & C each of which has a 1-to-many relation with a 
Comments table but I can't fathom how to set up the foreign key(s) in 
Comments without resorting to distinct A_id, B_id & C_id columns in 
Comments and enforcing 2 of the 3 columns be NULL for a given row. Seems 
ugly.

gvim



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