PHP学习：php+mysql实现数据库随机重排实例

<?php
//数据库连接就不写在这里面了
$s = isset( $_GET['s'] )?$_GET['s']:0;
$e = isset( $_GET['e'])?$_GET['e']:50;
$count =85000;
if( $s < $count )
{
 $sql = "select * from 表前缀_info where isget =0 order by id desc limit $s,$e ";
 $query = mysql_query( $sql );
 while( $rs = mysql_fetch_array( $query ) )
 {
  $id = $rs['id'];
  $sss = $rs['sss'];
  $typeid = $rs['typeid'];
  $isget = $rs['isget'];
  $sql = "insert into 表前缀_info_bak (id,表前缀,typeid,isget) values('$id','$sss','$typeid','$isget')";
  mysql_query( $sql ) ;
  echo $sql;
  //exit;
  $sqlu = "update 表前缀_info set isget=1 where id =".$rs['id'];
  mysql_query( $sqlu );
 }
 echo '<meta http-equiv="refresh" content="0;url=rand.php?s='.($s+50).'&e=50">正在处理数据,当前为'.$s.'条．．．．．．';
}
else
{
 echo '完成所有数据处理 <a href=rand.php>再随机排序一次</a>';
}
?>