javascript - 第二个下拉列表为空

问题描述

第一个下拉菜单应该选择所有学期数据，并且它有效。对于第二个下拉列表，它应该选择所有student_prg数据，但它不起作用（下拉列表为空）。

有什么方法可以让它工作吗？如果有任何其他方法可以使两个下拉菜单工作，请告诉我。

配置文件

<?php 

define('DBINFO','mysql:host=localhost;dbname=marketing_system');
define('DBUSER','root');
define('DBPASS','');

$conn = mysqli_connect("localhost","root","","marketing_system");

?>

测试报告.php

<div class="modal-body">
        <div class="form-group">
              <label for="title">Select Semester:</label>
              <select name="semester" class="form-control">
                  <option value="">--- Select Semester ---</option>

                  <?php
                    require('../setting/config.php');
                      $query = "SELECT DISTINCT semester FROM marketing_data ORDER BY semester DESC"; 
                      $do = mysqli_query($conn, $query);
                      while($row = mysqli_fetch_array($do)){
                          echo '<option value="'.$row['student_matric'].'">'.$row['semester'].'</option>';
                      }
                  ?>
              </select>
          </div>
          <div class="form-group">
              <label for="title">Select Programme:</label>
              <select name="prg" class="form-control">
                <option value="">--- Select Programme ---</option>

                <?php
                require('../setting/config.php');
                      $query2 = "SELECT DISTINCT student_prg FROM marketing_data ORDER BY student_prg DESC"; 
                      $do = mysqli_query($conn, $query2);
                      var_dump($do); die();
                      while($row = mysqli_fetch_array($do)){
                          echo '<option value="'.$row['student_matric'].'">'.$row['student_prg'].'</option>';
                      }
                ?>
              </select>
          </div>

数据库

mysql> describe marketing_data;
+---------------+------------------+------+-----+---------+--------------------+
| Field         | Type                 | Null | Key | Default | Extra          |
+---------------+------------------+------+-----+---------+--------------------+
| student_matric| varchar(10) unsigned | NO   | PRI | NULL    | auto_increment |
| student_prg   | text unsigned        | YES  |     | NULL    |                |
| semester      | varchar(10)          | YES  |     | NULL    |                |
| intake_year   | int(10)              | YES  |     | NULL    |                |
| student_city  | text                 | YES  |     | NULL    |                |
| city_lat      | varchar(20)          | YES  |     | NULL    |                |
| city_long     | varchar(20)          | YES  |     | NULL    |                |
| student_state | text                 | YES  |     | NULL    |                |
| state_code    | varchar(100)         | YES  |     | NULL    |                |
+---------------+------------------+------+-----+---------+--------------------+

标签： javascriptphpmysql

javascript - 第二个下拉列表为空

问题描述

解决方案

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