Dear All, thank you for your help, it was really efficient. I'll get by with it now. Thanks. -- Csaba
----- Original Message ----- From: "Bruno Wolff III" <[EMAIL PROTECTED]> To: "Együd Csaba" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Friday, June 27, 2003 5:10 PM Subject: Re: [SQL] Getting all rows even if not a member of any groups > On Fri, Jun 27, 2003 at 16:18:10 +0200, > Együd Csaba <[EMAIL PROTECTED]> wrote: > > > > This is absolutelly what I want, but I can't understand how it is working. > > Where can I find a descriptive (tale-like, for kids ... :) ) documentation > > about using joins? > > If you look at the documentation for the select command and page down a > bit there is a description of join syntax. Note that in 7.4 using > the explicit join syntax won't force join order. (This really only > affects cross joins and inner joins; left and right joins normally > can't be reordered.) > > You need a left join to pick up products that aren't in any group. > The parenthesis changed the join order so that group names were attached > to group ids before group ids were joined to products. This can have > performance implications. I think that this is probably the faster > way, but the other option would to have been to make the second join > a left join as well. > > > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.491 / Virus Database: 290 - Release Date: 2003. 06. 18. ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
