Re: ORDER BY col is NULL in UNION causes error?

Mike Benoit wrote:
> That helps some, but I'm sure it could be even more clear.
>
> The main issue is that you can't order by an expression computed by
> unions, correct? So couldn't the error message by something like:
>
> "ORDER BY on a UNION/INTERSECT/EXCEPT result must match existing result
> columns and not be an expression")));

Well, it can be an expression _if_ the expression _matches_ an existing
UNION column.

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  Bruce Momjian   bruce@momjian.us
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