Re: Are circular REFERENCES possible ?

I denis,

I don't know if you can use a circular REFERENCES, but why you try made a
references before the table is created (customers). You should create the
references after and use the foreign key if circular references does not
work.

William
"Denis Bucher" <dbucher@niftycom.com> a �crit dans le message news:
5.1.0.14.0.20010807114609.00a18490@mail.niftycom.com...
>
> Hello !
>
> I have a case where I wanted to do circular REFERENCES, is this
> impossible ?
>
> Just an example where it would be useful :
>
> We deliver to the *shops* of our *customers*.
> We have therefore two tables :
>   - customers (enterprise, financial information, and so on...)
>   - shop (with a name, street, phone number, name of manager)
>
> Now, each shop REFERENCES a customer so that we know
> to which customer belongs a shop.
>
> AND, each customer has a DEFAULT shop for deliveries, i.e. most
> customers only have one shop, or a main shop and many small ones.
> Therefore a customer should REFERENCES the 'main' or 'default' shop.
>
> Which leads to :
>
> CREATE TABLE shops ( id_shop SERIAL PRIMARY KEY, id_cust integer
REFERENCES
> customers, .......)
> CREATE TABLE customers ( id_cust SERIAL PRIMARY KEY, id_defaultshop
integer
> REFERENCES shops, .......)
>
> But this doesn't work ! Postgres complains like "ERROR:  Relation
> 'customers' does not exist"
> when creating 'shops'.
>
> Someone told me I should create a third table, ok, but in this case I
loose
> the total
> control about my logic... Do you have a suggestion ?
>
> Thanks a lot in advance !
>
> Denis
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org