jQuery无法正常运行

Question

When i select a value from the select box i need to get the corresponding values on the other field.this is my table

     id     first_name  last_name      stud_id      dob         hostel   class  room  bed   status
    175     siraj         k           WPGH00175   01-10-2016      7       28    41    2A    P
    176     nesru         kv          WPGH00176   31-10-2016      7       28    41    2B    P
    177     faizal        ep          WPGH00177   31-10-2016      7       28    41    2C    P
    179     mashoor       uv          WPGH00179   24-10-2016      7       28    41    2D    G

This is my view page

<div class="form-group" id="stud_id">
          <label for="student" class="col-sm-4 control-label">Student ID</label>
          <div class="col-sm-5">
            <select class="chosen-select chosen-transparent form-control" name="student" id="student">
             <option value="">--Select Student-- </option>
            <?php foreach ($students  as $row) { ?>
              <option value="<?php echo $row->id; ?>"><?php echo $row->stud_id; ?></option>
              <?php }?>
            </select>
          </div>
        </div>
        <div class="form-group">
          <label for="input01" class="col-sm-4 control-label">First Name:</label>
          <div class="col-sm-5" >
            <input type="text" class="form-control" id="first_name1" name="first_name" value="">
          </div>
        </div>

This is my jQuery

 <script type="text/javascript">
 $(document).ready(function(){

   $('#student').change(function(){ 
      var stud_id=$('#student').val();

      var url='<?php echo base_url(); ?>hostel/ajax_data';

      $.post(url,{s_id:stud_id}, function(data)
          {
        //alert();
             $("#first_name1").html(data);
          });
        });
     });
    </script>

This is my control

public function ajax_data()
{
  $stud_id = $_POST['s_id'];
  $data['result'] = $this->admin_model->ajax_name($stud_id);
  $this->load->view('hostel/ajax_data',$data);
}

This is my model

public function ajax_name($stud_id)
{
    $query=$this->db->get_where('student_hostel',array('id'=>$stud_id))->row();
    return $query;
}

when i give val instead of html the entire which i had given in view is showing. this is my view

<input type="text" class="form-control" id="first_name1" name="first_name" value="<?php echo $result->first_name;?>">

Answer 1

In view (hostel/ajax_data) you are printing whole html input and trying to place it again inside already loaded input using jquery- which doesn't make much sense. You can only echo

<?php echo $result->first_name;?> 

in view or directly in controller and using jquery put this response in the loaded input like this:

$("#first_name1").val(data);

If you need more data, not only first name, in that case you can make json.

Example:

Change in Model:

public function ajax_name($stud_id)
{
    $query=$this->db->get_where('student_hostel',array('id'=>$stud_id))->row_array(); //use row_array instead of row() to return an array
    return $query;
}

Change in Controller:

public function ajax_data()
{
  $stud_id = $_POST['s_id'];
  $result = $this->admin_model->ajax_name($stud_id);
  echo json_encode($result); //converting the array to json string and outputting it directly instead of using view
 }

Change in jQuery:

<script type="text/javascript">
 $(document).ready(function(){

   $('#student').on("change",function(e){ 
      var stud_id = $(this).val();

      var url='<?php echo base_url('hostel/ajax_data'); ?>';
     $.ajax({
        url: url,
        type: "post",
        data:{s_id: stud_id},
        success: function(result){
            var data = JSON.parse(result); //parsing server response to JSON object
            // Now data is an object. As your query in model is returning all fields, you can also use other fields like in this way: data.last_name, data.dob etc
            $("#first_name1").val(data.first_name);  //updating the input field with retrieved value. This way you also update other fields if necessary
        }
      });

   });
 });
</script>