php+mysql有数据，但查询不到数据有关问题

$query = "select name,class,schoolid from studentslist where class like '$query_class' and name like '$query_name' ";<br />
			<br />
			echo $query.'<br>';<br />
                        <br />
			$result = MySql_query($query, $id);<br />
<br />
//			if($result)echo 'query success';<br />
<br />
                        $totalnum = MySql_num_rows($result);<br />
echo $totalnum.' records found.';<br />
                        if ($totalnum < 1) {<br />
                            echo "<p align=left>未找到 " . $query_class . " 班姓名为 " . $query_name . " 的学生记录。</p>";<br />
                        }