mysql - Generating a sql query in php using for loop -

code :

 $nerd_result = mysql_query("select * nerd_profile nerd_reg_no = '$reg_no'"); $nerd_data = mysql_fetch_array($nerd_result); $tags = array(); $tags = explode(",",$nerd_data['nerd_interests']); for($i = 0; $i < sizeof($tags)-1; $i++) {     if($i != sizeof($tags)-2)     {     $sub_query = $sub_query."`tags` %".$tags[$i]."% or ";      }     else      {         $sub_query = $sub_query."`tags` %".$tags[$i]."% ";     } }     $proper_query = "select * `qas_posts` ".$sub_query." , `post_date` '%$today%'";  $result = mysql_query($proper_query);  while($each_qas = mysql_fetch_array($result)) 

description :

i adding clause along php variable in string , concatenating further variables clause come. in end when echo perfect query want

mysql_fetch_array()  

does not accept generated query rather if hard code , works perfect doing wrong ?? can ??

when doing string comparisons in mysql need make sure have quotes around comparison value.

$sub_query = $sub_query."`tags` '%".$tags[$i]."%' or "; 

and

$sub_query = $sub_query."`tags` '%".$tags[$i]."%' ";