Re: Question about joins, left outer and others

On 5/7/2010 2:38 PM, Jeff Ross wrote:
> This is going to be simple, I'm sure, but I'm stumped.  It's a little
> long but I thought as I wrote it out I'd get the aha! moment and since
> that didn't happen, here goes.
>

snip

> To get the output I want above, I'd think I'd need to do a left outer
> join like this:
>
> jross@wykids localhost# select ed_cat_name as "Level", pp_ed_cat_subject
> as "Subject", pp_ed_cat_institution as "Institution" from
> education_categories left outer join people_education_categories on
> (ed_cat_id = pp_ed_cat_id) where pp_ed_cat_pp_id = 1796;
>
> but that only gives me this:
>
> Level | Subject | Institution
> -----------+--------------------------------+-------------
> Bachelors | Elementary Education/Fine Arts |
> (1 row)
>

Its the "where pp_ed_cat_pp_id = 1796" that is causing it, not the join.

try adding "or pp_ed_cat_pp_id is null"

-Andy