Re: Quick question re foreign keys. - Mailing list pgsql-sql

From Phillip Smith
Subject Re: Quick question re foreign keys.
Date
Msg-id 009001c815e3$acc65e20$9b0014ac@wbaus090
Whole thread Raw
In response to Quick question re foreign keys.  (Paul Lambert <paul.lambert@autoledgers.com.au>)
List pgsql-sql
> My question therefore is, is it possible to create a foreign key that is
> conditional, i.e. only enforce the foreign key where the value in that
> table is not null.

My understanding from reading previous threads on this topic is the answer
is no, however you could make your own pseudo-foreign key using triggers to
do the same job, but only when your column is not null.

Not sure of the performance impact of doing this though - someone else may
be able to advise pros and cons in more detail.

Cheers,
~p


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