On Oct 7, 2011, at 9:46 AM, Simon Slavin wrote: > > On 7 Oct 2011, at 2:19pm, Igor Tandetnik wrote: > >> SQLite has a non-standard extension whereby aliases assigned to expressions >> in the SELECT clause may be used in the WHERE and other clauses: >> >> select 1+2 as alias from mytable where alias > 0; > > Arghhhhhhhh ! > > Okay, so I guess the form > >> select count(*) from ( >> select ... >> ); > > is necessary. But that defeats the point of me doing it in the first place: > I was hoping that COUNT(*) would be less resource-hungry than the real query,
assuming you have some other application level language you are using to get the data, you could stuff the result set into an array and then report the highest index of the array which might be faster than doing a second query for just the count. > and I suppose this form doesn't realise it doesn't need the values. > > Bah. Okay, I'll abandon that idea, then. > > Thanks, Igor. You saved me some hugely annoying support calls long after the > program was in the field. > > Simon. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
