asking about data base

function main2(){
 $sql = mysql_query("select * from clubs,venue where id<>".$_SESSION['userid']);

  $cnt开发者_如何学Python = 0;
  while($row = mysql_fetch_array($sql)like
 <td width="19%"><?php echo $row['club_name'];?></td>

when I use this code, my entry will be double show to me. What wrong with this like club name will be show twice to me.

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Probably because you don't JOIN the tables in your SQL query so the engine doesn't know how the data are related.

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You're doing a JOIN on the clubs and venue table. Depending on how your rows are saved, it'll give you all the possible matches. If you have a specific result in mind, please explain it and we'll need your database schema (the structure of your DB) as well.