On Wed, 6 Mar 2002 11:57:57 -0500
"Gregory Wood" <gregw@com-stock.com> wrote:
i do joins on a foreign key.
i.e.
from (table1 left join table2 on table1.id=table2.fk_table1_id) left join table3 on table1.id=table2.fk_table1_id...
do you know if postgres takes any advantage of that? or if there is an easier way to write it?
(i.e. tell it to join on foreign keys constraints)
> Explicit joins allow you to order the joins any way you want. When join
> conditions are in the WHERE clause, you don't have any control over the
> order in which the tables are joined.
>
> Additionally, when you do an explicit join, you can perform other types of
> joins, such as an inner join, outer join, etc.
>
> Personally I prefer doing explicit joins because it makes my SQL more
> readable to me; all the glue that joins the tables together is in the FROM,
> and the WHERE clause just limits the rows that I want returned.
>
> Greg
>
> ----- Original Message -----
> From: "David Eduardo Gomez Noguera" <davidgn@servidor.unam.mx>
> To: "postgres" <pgsql-general@postgresql.org>
> Sent: Wednesday, March 06, 2002 10:40 AM
> Subject: [GENERAL] joins?
>
>
> > Hello.
> > I am a bit new to databases. just still learning.
> > I havent got it right, but wht is the difference between a joint and a
> where clause?
> > specially "join on ".
> >
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--
ICQ: 15605359 Bicho
=^..^=
First, they ignore you. Then they laugh at you. Then they fight you. Then you win. Mahatma Gandhi.
-------------------------------気検体の一致------------------------------------
暑さ寒さも彼岸まで。
恋にししょうなし。恋はしあんの他。
アン アン アン とっても大好き