Re: default value returned from sql stmt
Richard Huxton <dev@archonet.com>
From: Richard Huxton <dev@archonet.com>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: David Salisbury <salisbury@globe.gov>, pgsql-general@postgresql.org
Date: 2012-03-30T08:22:09Z
Lists: pgsql-general
On 30/03/12 08:46, Pavel Stehule wrote: > 2012/3/30 Richard Huxton<dev@archonet.com>: >> On 29/03/12 23:28, Pavel Stehule wrote: >>> >>> select anum from t1 where anum = 4 >>> union all select 100 limit 1; >> >> >> I'm not sure the ordering here is guaranteed by the standard though, is it? >> You could end up with the 4 being discarded. > > A order is random for only "UNION", "UNION ALL" should to respect > order. But I didn't check it in standard. Let's put it this way - a quick bit of googling can't find anything that says the order *is* guaranteed, and (almost?) no other operations do so by default. -- Richard Huxton Archonet Ltd