Re: sql join question - Mailing list pgsql-general

From Scott Frankel
Subject Re: sql join question
Date
Msg-id a435cfd8b41af5ab914176d17dae94c4@pacbell.net
Whole thread Raw
In response to Re: sql join question  (Ragnar Hafstað <gnari@simnet.is>)
List pgsql-general
Got it.  Thanks!
Scott


On Mar 1, 2005, at 10:52 PM, Ragnar Hafstað wrote:

> On Tue, 2005-03-01 at 16:51 -0800, Scott Frankel wrote:
>> Sweet!  And not so sweet.
>>
>> The natural join worked beautifully with my test schema; but it failed
>> to yield any rows with my real-world schema.  I think I've tracked
>> down
>> why:  duplicate column names.  i.e.:
>> ...
>>     CREATE TABLE palettes (palette_pkey SERIAL PRIMARY KEY,
>>         palette_name text UNIQUE DEFAULT NULL,
>>         qwe text);
>>
>>     CREATE TABLE tones    (tone_pkey SERIAL PRIMARY KEY,
>>         tone_name text UNIQUE DEFAULT NULL,
>>         palette_pkey integer REFERENCES palettes,
>>         qwe text);
>>
>> Are the 'qwe' columns in both tables clobbering each other and
>> preventing the
>> join from succeeding?
>
> the docs really explain this better than I can, but a
>   table1 NATURAL JOIN table2
> is shorthand fo a
>   table1 JOIN table2 USING (list_of_common_keys)
>
> so:
> select color_name from palettes
>    join tones USING (palette_pkey)
>    join colors USING (tone_pkey)
>   where palette_name='plt1';
>
> see:
> http://www.postgresql.org/docs/8.0/interactive/sql-select.html
>
> gnari
>
>
>


pgsql-general by date:

Previous
From: Michael Fuhr
Date:
Subject: Re: aggregate functions on massive number of rows
Next
From: Tom Lane
Date:
Subject: Re: Vacuum time degrading