Re: Outer join statement ?

Hello,
There are 2 ways of doing outer joins, both are relatively expensive
from the CPU time point of view
1. Create a function that returns the ojined value, or null if the value
does not exists in the secod table
2. Use a union beetwen a left join and a straight select with a where
condition. Next there's an example inspired from the Adison Westley book (I
suggest you grab a copy from the postgresql site. (/docs)

select customer.name,salesorder.order_id from customer join salesorder
on customer.cust_id=salesorder.fk_cust_id union all select
customer.name,null::int4 from customer where customer.cust_id not in (select
fk_cust_id from salesorder);

Probably an improvement here is to use exists on the second select, but
I didn't have the time to document.
Anyway, this will not work embedded in a view ("union all" is not
supported in views).

Alexander

"Nasdaq" <fb(at)techbourse(dot)com> wrote in message
news:fb-3008002344340001(at)du-211-67(dot)lyon(dot)dialup(dot)freesurf(dot)fr(dot)(dot)(dot)
> The statement "Outer Join" is not available in Postgres ?
> Is there an extension provided by a third company that implement this
> functionnality ?
>
> If not do you know when this functionnality will be available in
> Postgres ?
>
> Thank
>
> Fred
>
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