出现这个警告是为什么?代码在下面
<?php
header("content-type:text/html;charset=utf-8");
mysql_connect("localhost",'root','');
mysql_select_db("classmate");
mysql_query("set names utf8");
$query=mysql_query("select*from classmate");
while($arr=mysql_fetch_object($query)){
echo ($arr->name);
echo "<br />";
}
?>