Jean-Christian Imbeault <jc(at)mega-bucks(dot)co(dot)jp> writes:
> TAL=# select max(req_del_date1, req_del_date2, req_del_date3) as ma1 from
> invoices where ma1 <= now();
> ERROR: Attribute "ma1" not found
>
> What is wrong with my syntax?
Try either of:
SELECT max(req1, req2, req3) AS max FROM invoices WHERE max(req1, req2, req3) <= now()
SELECT * from (select max(req1, req2, req3) AS max FROM invoices) WHERE max <= now()
Whichever seems clearer to you, I think postgres actually runs the two the
same way. Note, you should mark your function immutable so postgres knows it
can optimize the second case into the first.
--
greg