<?php
session_start();
session_register("user_id");
session_register("user_name");

//链接到MySQL服务器

$db_host = "localhost";
$db_user = "root";
$db_pass = "";
$db_name = "db_name";
$link = @mysql_connect($db_host, $db_user, $db_pass);
$query="select * from shop_new";
$query1="select * from shop_jilu";
$query2="select * from users";
//select * from shop_new order by id DESC limit 3
$result=mysql_query($query,$link);
$result1=mysql_query($query1,$link);
$result2=mysql_query($query2,$link);
$rows=mysql_num_rows($result);
$rows1=mysql_num_rows($result1);
$rows2=mysql_num_rows($result2);
echo $rows;
echo $rows1;
echo $rows2;
?>

然后就会出现几个Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in c:\AppServ\www\phonecard\index.php on line 22
这样的错误,为什么会出错