RE: [PHP] Fastest way to get table records' number

> > > At 10:35 AM -0400 3/19/08, Nathan Nobbe wrote: > > > >On Wed, Mar 19, 2008 at 9:42 AM, Andrew Ballard <aballard@gmail.com> > > 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. > > > what about SELECT MAX(id) FROM table :) But that's not the same thing. If any rows have been deleted, then this would give the wrong answer. Edward