On Aug 3, 2007, at 2:24 AM, Dani Castaños wrote:
Josh Tolley escribió:
On 8/2/07, Dani Castaños <[EMAIL PROTECTED]> wrote:
Hi all!
Is it possible to have a foreign key where referenced table is in
another database?
Thank you in advance
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Unless you use things like dblink to make two separate databases
think
they're one database, you really can't do anything where one database
depends on another. Your best bet, if you can have both data sets on
the same machine, is to stick them in two separate schemas, and then
you can have foreign keys on a table in one schema referencing a
table
in another schema. That's (in part) what schemas are for in the first
place -- to separate logically distinct data sets while allowing
accesses between the two when necessary.
If for whatever reason having all the data on one machine isn't
possible, you can try using dbi-link or dblink to create links
between
the two databases and do foreign keys that way, but I've never used
either, so that might not work/make sense/be possible, etc.
-Josh
Thanks Josh!
I use dblinks for queries, but I'm pretty sure you can't use it in
constraints definitions.
My situation is that I have one main database and many customer's
databases. In main database there is a languages table, and
customers databases must use the language_id. Then, I don't want to
create languages table in each customer db, that's the reason why i
was trying to do a foreign key from customer db to main db.
Not directly as pg constraints, no. But, what you can do is create a
trigger that simulates the same effect.
Erik Jones
Software Developer | Emma®
[EMAIL PROTECTED]
800.595.4401 or 615.292.5888
615.292.0777 (fax)
Emma helps organizations everywhere communicate & market in style.
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