So select count (*) from ...
Doesn't require a crystal ball and returns the number of rows but Select count(*) from ... Limit x Dies need one, interesting On Saturday, 5 March 2016, Igor Tandetnik <igor at tandetnik.org> wrote: > On 3/5/2016 12:20 PM, Paul Sanderson wrote: > >> If it computes many things and doesn't return many rows then I don't >> really care. I only want to know how many rows a query will return >> before I execute it in full. >> > > That would require a crystal ball or a time machine. Absent those, it's > impossible to know how many rows a query will produce until it actually > runs and produces them. > > Again, you can wrap an arbitrary query like this: > > select count(*) from ( > select whatever ... > ); > > This query always returns exactly one row and one column, with the value > being the number of rows that the inner query would have returned. Is this > not what you want? Of course, it would take approximately as much time to > run this new query as it would the original query. > -- > Igor Tandetnik > > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > -- Paul www.sandersonforensics.com skype: r3scue193 twitter: @sandersonforens Tel +44 (0)1326 572786 http://sandersonforensics.com/forum/content.php?195-SQLite-Forensic-Toolkit -Forensic Toolkit for SQLite email from a work address for a fully functional demo licence
