On 2016-05-09 11:45, liviuslivius [email protected] [firebird-support] wrote: > Hi, > > This is not specific to Firebird question but: > is something in SQL standard specification about sorted fields must > be > also returned? > I mean: > > SELECT > [FILM_DATE,]FILM_TITLE > FROM > FILMS > ORDER BY FILM_DATE, FILM_TITLE > > is [FILM_DATE] required by SQL standard or it is optional or SQL > standard tell nothing about this?
I don't have the SQL standard at hand right now, so I can't double check. As far as I know, the SQL standard allows you to sort on any field, even if it is not in the select list (with the exception of course of ordering by column index). Mark
