php - 此代码没有从学生表中获取数据

Question

我有两个表，student 和 Stusub，
学生有 sname 和 suni_roll_no
和 stusub 具有 suni_roll_no 和 sub_code。
我请求 sub_code 并且此代码未显示数据库的结果，

<?php
include("db.php");  

$sub_code =$_REQUEST['sub_code'];

$query = @mysql_query("SELECT student.sname, student.sroll_no
FROM student INNER JOIN stusub
ON student.suni_roll_no=stusub.suni_roll_no where sub_code  = '$sub_code';");
while($test = @mysql_fetch_array($query))
        {
            $sub_code = $test['sub_code'];  
            echo "<tr align='center'>"; 

            echo"<td><font color='black'>" .$test['sname']."</font></td>";
            echo"<td><font color='black'>" .$test['sroll_no']."</font></td>";


            echo "</tr>";
        }
        mysql_close($conn);
        ?>

Answer 1

不应放入查询内；

try it

    <?php
    include("db.php");  

    $sub_code =$_REQUEST['sub_code'];

    $query =mysql_query("SELECT student.sname, student.sroll_no
    FROM student INNER JOIN stusub
    ON student.suni_roll_no=stusub.suni_roll_no where sub_code  = '$sub_code'");
    while($test =mysql_fetch_array($query))
            {
                $sub_code = $test['sub_code'];  
                echo "<tr align='center'>"; 

                echo"<td><font color='black'>" .$test['sname']."</font></td>";
                echo"<td><font color='black'>" .$test['sroll_no']."</font></td>";


                echo "</tr>";
            }
            mysql_close($conn);
            ?>