On 9 Dec 1999, Sascha Ziemann wrote:
> Hi,
>
> I have two tables "user_t" and "email_alias_t". The "user_t" table
> has the two fields "last_name" and "linux_login" and the
> "email_alias_t" table has the two fields "login" and "alias".
>
> In some rows in the "user_t" table the entry "linux_login" is NULL.
>
> Now I need all rows from "user_t" and for those rows which have a
> "linux_login" I need the "alias" column from "email_alias_t".
>
> My SQL book descibes the *= operator which should be used for those
> queries but Postgres does not have it. I found out that it is
> possible to do the select with a union. This union:
In the PostgreSQL exist a operator *= , but is used for a array
(text[] ..etc), (now is distributed in the contrib tree).
I not sure, if I good undertend you, but good resolution for your
problem is prabably JOIN. But it not implement in PgSQL now
(it will in 7.0) :-(
Karel