Re: Allow an alias to be attached directly to a JOIN ... USING

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Wolfgang Walther <walther@technowledgy.de>, Fabien COELHO <coelho@cri.ensmp.fr>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-11-14T08:52:39Z
Lists: pgsql-hackers
On 2020-08-03 19:44, Wolfgang Walther wrote:
> So given this:
> 
> SELECT x.id FROM a LEFT JOIN b USING (id) AS x
> 
> will this return NULL or a.id for rows that don't match in b? This
> should definitely be mentioned in the docs and I guess a test wouldn't
> be too bad as well?

This issue is independent of the presence of the alias "x", so I don't 
think it has to do with this patch.

There is a fair amount of documentation on outer joins, so I expect that 
this is discussed there.

-- 
Peter Eisentraut
2ndQuadrant, an EDB company
https://www.2ndquadrant.com/



Commits

  1. Allow an alias to be attached to a JOIN ... USING

  2. Add p_names field to ParseNamespaceItem