On Tue, Mar 9, 2010 at 7:15 AM, Tim Romano <tim.rom...@yahoo.com> wrote: > Of these three: > > select c from T where 1=2 // returns 0 rows > select min(c) from T where 1=2 // returns 1 row > select min(88,99) from T where 1=2 // returns 0 rows > > the only case that "threw" me is the second one, where a row is returned > despite a WHERE condition that should yield an empty set (or so I thought).
The first and last cases will run for each row in the WHERE clause. The second case is aggregating over all c, and will always return one row, even if the WHERE clause selects many rows, so it is consistent for it to return one row if the WHERE clause selects for no rows. It's as if you coded it like this: SELECT min(SELECT c FROM t WHERE ...) meaning the minimum of that set of inputs, and if that set is empty, there is no minimum, so you get a result of NULL, but not no result, if you see what I mean. -scott _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
