Re: more information on JOINs

Thanks for this reference, I have  been here.  I guess my problem is 
that I don't understand a need for a 'join' that is returning NULLs. If I 
understand <left> <right> <outer> JOINs correctly, they are returning 
columns that contain NULLs. 

An example please where I would want this result. I have created a 
job tracking system that includes invoicing, collections reporting, 
aging. When I first learned to do the INNER JOIN ON, I replaced the 
processing that I was doing in my client app and let Postgres do it. 
So now I am examining and studying the other joins. I just can not 
figure out why I would EVER want one. Which leads me to think that I 
just don't understand them.

Please, if someone has a good example......


Ted 
tedpet@symcom.com

-----Original Message-----
From: Francesco Casadei <f_casadei@libero.it>
To: postgresql <pgsql@symcom.com>
Date: Sat, 22 Sep 2001 17:40:57 +0200
Subject: Re: [SQL] more information on JOINs

> On Sat, Sep 22, 2001 at 08:11:03AM -0400, postgresql wrote:
> > Where can I get more information and  examples on using 
JOINs. I 
> > have been reading over the Chapter 2 on from the interactive 
user 
> > docs but I need a little more in the  way of examples. I am having 
a 
> > problem understanding when I would need a LEFT or RIGHT 
JOIN. 
> > 
> > Please, a 'point' in the right (no pun intended) direction would be 
> > appreciated.
> > 
> > Ted
> > 
> > 
> > 
> > ---------------------------(end of
> broadcast)---------------------------
> > TIP 6: Have you searched our list archives?
> > 
> > http://archives.postgresql.org
> > 
> > end of the original message
> 
> Take a look at the reference manual, part I "SQL Commands":
> 
> 
http://www.ca.postgresql.org/users-lounge/docs/7.1/reference/sql-s
elect
> .html
> 
>     Francesco Casadei