<?
$db_menu=mysql_pconnect("localhost","website_gzerp","gzerp");
if(!$db_menu)
{
echo "ERROR:Could not connect to database.Please try again later.";
exit;
}
mysql_select_db("$erp_db");
$query="select group_name,link_page,group_id from hmenu";
$result=mysql_query($query);
echo $result;
$num_results=mysql_num_rows($result);
echo "/$num_results".$num_results;
while($row=mysql_fetch_row($result))
{
echo $row["group_id"],$row["group_name"],$row["link_page"];
echo"finshed\n";
}
?>
我在测试上面一段程序的时候出现了下述信息。
是什么原因引起的呢？

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/website/public_html/test2/1/test0.php on line 13
/
Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /home/website/public_html/test2/1/test0.php on line 15

这是什么原因引起的警告信息？