Обсуждение: constraint with check
Hi
im trying to create foreign key constraint which checks not only the existence of key in foreign table, but it has to check if node field has value=true
but i don't know how to do that, so im asking for help.
add CONSTRAINT "nc_fk" FOREIGN KEY ("Id1")
REFERENCES "wg"."entities"("Id"),
check (node=true)
thanx in advance
--
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Viktor Bojović
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Wherever I go, Murphy goes with me
On 2010-12-13, Viktor Bojović <viktor.bojovic@gmail.com> wrote:
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> Hi
> im trying to create foreign key constraint which checks not only the
> existence of key in foreign table, but it has to check if node field has
> value=3Dtrue
> but i don't know how to do that, so im asking for help.
> alter table wg.nc
> add CONSTRAINT "nc_fk" FOREIGN KEY ("Id1")
> REFERENCES "wg"."entities"("Id"),
> check (node=3Dtrue)
you can't do that.
add a node column to wg (and a check node is not distinct fron true constaint and default true) then do this
alter table wg.ncadd CONSTRAINT "nc_fk" FOREIGN KEY ("Id1",node) REFERENCES "wg"."entities"("Id",node);