php 删除mysql数据库的重复记录

<?php
set_time_limit(13600);  //设置时间
$conn=mysql_connect('localhost','root',''); //连接数据库
mysql_select_db('shuju',$conn);
mysql_query("set names 'gbk'");

$query = mysql_query("select min(id) as mid from taobaoguanjianci group by title");   

while($row = mysql_fetch_array($query))
 {

mysql_query("INSERT into taobaoguanjiancitmp select id,cid,title,cat,level3,cname from taobaoguanjianci where id=$row[mid]");
 }
?>