error in mysql_num_rows while checking select statement from db

Question

i am just checking wheather the name or the nick already exists or not. here is the code.m using mysql 5.5.24 with php 5.3.13 with apache 2.2.22.

$query="SELECT realname,nick FROM main WHERE `nick`='$nick' OR `email`='$email'";
$res=mysql_query($query);
if(mysql_num_rows($res)==0){

if it returns 0 thn the connection string follows and the insert statement. the problem is i am getting an error with mysql_num_rows statement

 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean

everythng was working fine but later some updates changed. do i need to switch to mysqli if so how.

See [this answer](http://stackoverflow.com/a/11674313/250259) for how to troubleshoot this. — John Conde, Nov 21 '13 at 18:32
Did you include the `mysqli` tag just to be told off about not using it? — Tom Fenech, Nov 21 '13 at 18:35

score 1 · Accepted Answer · answered Nov 21 '13 at 18:47

1

Use error checking first for $res to know the specific error

if($res){
   if(mysql_num_rows($res)==0){.......}
}
else{
echo mysql_error();
}

answered Nov 21 '13 at 18:47

Tim Knox

1 Answers1