Re: Full outer join? Cross product? How to blend two queries into single row? - Mailing list pgsql-general

On Thu, Sep 4, 2008 at 3:22 PM, Sam Mason <sam@samason.me.uk> wrote:
> On Thu, Sep 04, 2008 at 03:43:33PM -0500, D. Dante Lorenso wrote:
>> I came up with this query that works, but seems overly complicated:
>>
>>   SELECT a.col1, a.col2, b.col3, b.col4
>>   FROM
>>      (SELECT col1, col3, TRUE AS join_column
>>       FROM mytable
>>       WHERE uid = 'abc') a
>>     FULL OUTER JOIN
>>      (SELECT col3, col4, TRUE AS join_column
>>       FROM mytable
>>       WHERE uid = 'def') b
>>     ON (a.join_column = b.join_column);
>>
>> Is this how to do it, or is there a simpler syntax I'm missing?
>
> The "ON" clause is just a normal expression, so you can just put a
> "TRUE" in there if you want a cross join.  I.e. the following is a
> minimal full outer cross join:
>
>  SELECT * FROM foo FULL OUTER JOIN bar ON TRUE;

can't you just drop the on clause altogether?