php+MySQL判断update语句是否执行成功的方法

$rs=MySQL_query($sql);
if(mysql_affected_rows())
echo "sql执行成功";
else
echo "sql执行失败";

<?php
  /* 连接数据库 */
  mysql_pconnect("localhost", "mysql_user", "mysql_passWord") or die ("Could not connect" . mysql_error());
  mysql_select_db("mydb");
  /* Update 记录 */
  mysql_query("UPDATE mytable SET used=1 WHERE id < 10");
  printf ("Updated records: %d\n", mysql_affected_rows());
  mysql_query("COMMIT");
?>