Re: [HACKERS] Foreign keys: unexpected result from ALTER TABLE... ADD CONSTRAINT...

Jan Wieck wrote:
>
> With CREATE CONSTRAINT TRIGGER (which I added first so someone could
> already work on pg_dump - what noone does up to now :-( ), you can
> specify deferrability and initial deferred state for the trigger. And
> it correctly sets up the PK<->FK tables relationships in pg_trigger,
> so that DROPping one of them removes all the triggers using it from
> the other one. Needless to say that dropping and recreating a PK
> table looses all the references! But dropping and recreating the
> referencing tables therefore doesn't put the PK table into an
> unusable state.
>

Oracle solves these kind of problems by having a CREATE OR REPLACE command,
that keeps as much of related objects as possible if there is already an
object by that name.

Does anyone know if it is ANSI SQL ?

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Hannu