编辑记录时，我希望下拉列表显示以前选择的值。
代码是below:-

<div class="modal fade" id="edit_model" tabindex="-1" role="dialog"  aria-hidden="true" style="display: none;">
  <div class="modal-dialog modal-lg">
     <div class="modal-content">
        <div class="modal-header">
           <h6 class="modal-title" >Model Title</h6>
           <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
        </div>
        <div class="modal-body">
           <form action="filename.php" method="post">
              <div class="form-group row">
                 <div class="col-md-1"></div>
                 <div class="col-md-3">
                    <input type="text" name="first_name" placeholder="First Name" id="first_name" class="form-control rs_input" required >
                 </div>
                 <div class="col-md-3">
                    <input type="text" name="last_name" placeholder="Last Name" id="last_name" class="form-control rs_input" required >
                 </div>
                 <select class="form-control" id="dropdown_id" name="dropdown_name">
                       <option >Select Value</option>

                       <?php
                          $dropdown = mysqli_query($connect, "SELECT * FROM table") or die(mysqli_error($connect));
                          while ($fetch_data = mysqli_fetch_array($country)) {
                              ?>
                       <option value="<?php echo $fetch_data['id']; ?>"><?php echo $fetch_data['name']; ?></option>
                       <?php
                          } ?>
                    </select>
              </div>
             </div>
        </div>
    </div>
</div>

jquery:-

$('.class_name').on('dblclick',function(){
var value = $(this).attr("id");

$.ajax({
  url:"ajax/filename.php",
  method:"POST",
  data:{value:value},
  dataType:"json",
  success:function(data){

    $('#first_name').val(data.first_name);
    $('#last_name').val(data.last_name);
    $('#dropdown_id').val(data.dropdown_value);
)};
)};

为了澄清，我希望在用户编辑记录时，在下拉列表中选择先前选择的值，即记录中存在的值。感谢您的帮助。