Re: [GENERAL] FOREIGN KEY syntax - Mailing list pgsql-general

From Bruce Momjian
Subject Re: [GENERAL] FOREIGN KEY syntax
Date
Msg-id 200003070300.WAA02732@candle.pha.pa.us
Whole thread Raw
In response to Re: [GENERAL] FOREIGN KEY syntax  ("Oliver Elphick" <olly@lfix.co.uk>)
Responses Re: [GENERAL] FOREIGN KEY syntax
List pgsql-general
Oliver Elphick wrote:

> Andrzej Mazurkiewicz wrote:
>   >> And what is MATCH FULL?
>   >    [Andrzej Mazurkiewicz] I would not like to speculate perhaps
>   >somebody else knows exact answer.
>
> MATCH FULL:
>   Either all referencing columns must be null, or all must have values.
>
> MATCH PARTIAL:
>   "if any columns are non-null, there must be at least one row in the
>    referenced table that could satisfy the constraint if the other null
>    values were correctly substituted."

    As I read the SQL3 spec draft, it's that if at least one
    of the columns is NULL, no check is done at all.

    Could be wrong, will lookup at Thursday when back in
    Hamburg.


Jan from Philly


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