On 30/10/2019 09:04, Fabien COELHO wrote:
>
>> I think possibly what the spec says (and that neither my patch nor
>> Peter's implements) is assigning the alias just to the <join column
>> list>.
>
> I think you are right, the alias is only on the identical columns.
>
> It solves the issue I raised about inaccessible attributes, and
> explains why it is only available with USING and no other join variants.
>
>> So my original example query should actually be:
>>
>> SELECT a.x, b.y, j.z FROM a INNER JOIN b USING (z) AS j;
>
> Yep, only z should be in j, it is really just about the USING clause.
My reading of SQL:2016-2 7.10 SR 11.a convinces me that this is the case.
My reading of transformFromClauseItem() convinces me that this is way
over my head and I have to abandon it. :-(