Re: how to determine if a mysql query returns an empty set?

On Thu, Apr 23, 2009 at 2:12 PM, Adam Williams <awilliam@mdah.state.ms.us> wrote: > Is there a way to determine if a mysql query returns an empty set?  I am > selecting 10 results at a time with a limit statement and need to know when > i've ran out of rows.  I've only got 2 rows in the database, so when I start > with row 10, it returns an empty set.  I have the following code: > > //running this query gives "Empty set (0.00 sec)" in mysql console. > > $get_requests = "select form_id, full_name, email, phone, division, > location, date_format(time_of_request, '%m-%d-%Y %r') as time_of_request, > contact_time, problem, accepted_by, date_format(accepted_time, '%m-%d-%Y > %r') as accepted_time, resolution, date_format(resolution_time, '%m-%d-%Y > %r') as resolution_time from form where ((stage = 'Closed') && (email = > 'awilliam' )) order by resolution_time limit 10 , 10" > > //checks to see if it returns nothing, then print that you are at the end of > the results > >               if (!$mysqli_get_requests = > mysqli_query($mysqli,$get_requests)) >                       { >                       echo "You have reached the end of the results. >                       Please press the back button. >                       <form action=/helpdesk/login.php method=post><input >                       type=submit value=Back >                       name=submit></form></body></html>"; >                       exit; >                               } > > but that doesn't work, because I guess an empty set is not false, 0, or > NULL? > > > It won't be any of those because the query is successful even if it returns no records. You could use http://us2.php.net/manual/en/mysqli-stmt.num-rows.php to determine how many rows were returned. Andrew