如何快速比较数据表结构的改变？

<?php
   $conn = mysql_connect('localhost','**','***');
   mysql_select_db("test");
   $sql = "describe oldtable";
   $sql2 = "describe newtable";
   
   $res = mysql_query($sql);
   $res2 = mysql_query($sql2);
   $result = mysql_fetch_array($res);
   $reslut2 = mysql_fetch_array($res2);
   
   print_r(array_diff($result,$result2));
   echo "<hr/>";
   print_r(array_diff($result2,$result));