On Wed, Mar 19, 2008 at 10:53 AM, tedd <tedd.sperling@xxxxxxxxx> wrote: > > > > At 10:35 AM -0400 3/19/08, Nathan Nobbe wrote: > >On Wed, Mar 19, 2008 at 9:42 AM, Andrew Ballard <aballard@xxxxxxxxx> wrote: > > > >> That works; I'm just wondering why you went with a count on an 'ID' column > >> rather than COUNT(*). > > > > > >ouch, it looks like im horribly wrong :O > >mysql> select count(*) from table; > >+----------+ > >| count(*) | > >+----------+ > >| 361724 | > >+----------+ > >1 row in set (0.90 sec) > > > >mysql> select count(id) from table; > >+------------+ > >| count(did) | > >+------------+ > >| 361724 | > >+------------+ > >1 row in set (4.56 sec) > > > >-nathan > > That surprised me as well. > > I thought that (*) meant "look up everything" and would have figured > that (id) would have been quicker. > > You generally want to explicitly specify column names rather than using SELECT *, because it returns everything even if you don't need it. But for aggregate COUNT, I'm not surprised by the results Nathan got. Andrew -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
