javascript - 获取在嵌套循环中动态生成的选定选项值

Question

这是我正在开发的功能。我需要获取 while 循环内的所选选项。每次我尝试通过 select id 获取所选值时，它仅获取该行其余部分的最后一个所选值。

请帮助我。如何获取并存储全表数据？

function generate_schedule($con,$sy,$year_id){

    $time = array(1=>'9:30-11:00',2=>'11:30-1:00',3=>'1:30-3:00',4=>'3:15-4:45');
    $days = array(1=>'Sunday',2=>'Monday',3=>'Tuesday',4=>'Wednesday',5=>'Thursday',6=>'Friday',7=>'Saturday');
    $rooms=array(1=>'302',2=>'303',3=>'304',4=>'701',5=>'702',6=>'704',7=>'901',8=>'902',9=>'1402',10=>'1405');
    $yls=mysqli_query($con,"SELECT * FROM year_level_subject as yls join subjects as s on yls.subj_id=s.subj_id where yls.year_id='$year_id'");
    $num=mysqli_num_rows($yls);
    $x = 0;
    echo '<table class="table table-bordered table-hover" id=" datatable">';
    echo '<thead><tr><th>Time</th><th>Days</th><th>Subject</th><th>Teacher</th><th>Room</th></tr></thead>';
    while($row=mysqli_fetch_assoc($yls)){
        extract($row);
        echo '<tr>';
        echo '<td><select id ="seltime" ><option value=0>Select Time</option>';
        foreach($time as $key => $value) {
            echo '<option value='.$key.'>';
            echo $value .'</option>';
        }
        echo '</select></td>';
        echo '<td><select class="selday" ><option value=0>Select Day</option>';
        foreach($days as $key => $value) {
            echo '<option value='.$key.'>';
            echo $value .'</option>';
        }
        echo '</select></td>';
        echo '<td>'.$subj_desc.'</td>';
        $teach = mysqli_query($con,"SELECT * FROM teachers");
        echo '<td><select id="selteacher" onchange="schedata(this)"><option value=0>Select Teacher</option>';
        while($row=mysqli_fetch_assoc($teach)){
            extract($row);
            echo '<option value='.$teach_id.'>'.$teach_fname.' '.$teach_mname.' '.$teach_lname.'</option>';
        }
        echo '</select></td>';
        echo '</select></td>';
        echo '<td><select name ="selroom" ><option value=0>Select Room</option>';
        foreach($rooms as $key => $value) {
            echo '<option value='.$key.'>';
            echo $value .'</option>';
        }
        echo '</select></td>';
        echo '</tr>';
    }
    echo '</table>';
}

Answer 1

您没有为您的选择元素提供名称属性

 echo '<td><select id="selteacher" onchange="schedata(this)"  >

为此命名

 echo '<td><select id="selteacher" name="selteacher" onchange="schedata(this)"  >