Fredric Fredricson wrote:
> But if you change the column names in the second SELECT in the UNION this is
> ignored:
> # SELECT c1,c2 FROM (SELECT 1 AS c1, 2 AS c2 UNION SELECT 2 AS c3, 1 AS c4)
> AS x;
> c1 | c2
> ----+----
> 1 | 2
> 2 | 1
> Apparently, in a UNION the column names are derived from the first statement
> only.
The example upthread demonstrates that in certain contexts, column positions
are relevant whereas column names are not. The modified query you show here
doesn't lead to any different conclusion.
The allegation that row.* doesn't come with a deterministic column order
remains pretty much unsubstantiated at this point.
Best regards,
--
Daniel
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