在Codeigniter中使用Ajax更新数据库记录

Question

I am trying to update database records using ajax from the ajax response, getting success message but the actual database records are not updated at all. But it wonder how the ajax response should throw the success message while the query is not updating the database.

VIEW:

 // AJAX code to update the database // update marks when form is submitted $('#updateMarks').on('submit',function(event) { event.preventDefault(); var practical_mark = $("#mark_written").val(); var written_mark = $("#mark_practical").val(); var comment = $("#comment").val(); var mark_id = $("#mark_id").val(); $.ajax({ type: "POST", url: "<?php echo site_url('admin/exam_marks_update'); ?>", data: { practical_mark : practical_mark, written_mark: written_mark, comment : comment, mark_id : mark_id }, success: function(response) { alert("success"); }, error: function(){ alert("Error"); }, }); }); 

 <?php foreach($marks as $row2): ?> <form method="post" role="form" id="updateMarks"> <tr> <td class="text-center"><?php echo $student['name']; ?></td> <td> <!-- create two col table for marks category --> <table class="table table-bordered table-hover toggle-circle"> <thead> <tr> <th data-toggle="true" class="text-center"><?php echo get_phrase('written_exam'); ?></th> <th data-toggle="true" class="text-center"><?php echo get_phrase('practical_exam'); echo get_phrase('_(out_of_100)'); ?></th> </tr> </thead> <tbody> <tr> <td class="text-center"><input type="number" value="<?php echo $row2['written_mark_obtained'];?>" id="mark_written" name="mark_written" class="form-control" /></td> <td class="text-center"><input type="number" value="<?php echo $row2['practical_mark_obtained'];?>" id="mark_practical" name="mark_practical" class="form-control"/></td> </tr> </tbody> </table> <!-- end create two col table for marks category --> </td> <td class="text-center"><textarea class="form_control" id="comment" name="comment" rows="4" > <?php echo $row2['comment'] ?> </textarea></td> <td class="text-center"> <input type="hidden" id="mark_id" name="mark_id" value="<?php echo $row2['mark_id'];?>" /> <button type="submit" class="btn btn-block btn-success btn-md"><i class="icon pe-pen" aria-hidden="true"></i><?php echo get_phrase('update'); ?></button> </td> </tr> </form> <?php endforeach; ?> 

Controller:

 function exam_marks_update(){ $data['written_mark_obtained'] = $this->input->post('written_mark'); $data['practical_mark_obtained'] = $this->input->post('practical_mark'); $data['comment'] = $this->input->post('comment'); $this->crud_model->update_student_marks($data, $this->input->post('mark_id')); } 

MODEL

 function update_student_marks($data, $mark_id){ $this->db->where('mark_id', $mark_id); $this->db->update('mark', $data); } 

Answer 1

Your Controller retrieving inputs which doesn't exists... you need to pass your name, id as inputs and not the value which you echo... see as Controller:

function exam_marks_update(){
$data = array(
    'written_mark_obtained'   => $this->input->post('written_mark'),
    'practical_mark_obtained' => $this->input->post('practical_mark'),
    'comment'                 => $this->input->post('comment')
);
$this->db->where('mark_id', $this->input->post('mark_id'));
$this->db->update('mark', $data);
}

and change this:

  var comment        = $("#comment").val();

to

  var comment        = $("#comment").html();

As comment is textarea...

Answer 2

Jquery ajax success callback function is always called if the request to server succeeds. You need to return response data from server to verify when database operation was successful or not. I have edited your code , this might work for you.

MODEL

 function update_student_marks($data, $mark_id){
      .....
      return $this->db->update('mark', $data);
    }

Controller::

  function exam_marks_update(){
      .....
      if($this->crud_model->update_student_marks($data, $this->input->post('mark_id'))){
       echo json_encode(array('success' => true));
       exit;
     } else {
      echo json_encode(array('success' => false));
      exit;
    }
 }

View

 $.ajax({
        type: "POST",
        url: "<?php echo site_url('admin/exam_marks_update'); ?>",
        dataType :'json',
        data: { practical_mark : practical_mark, 
               written_mark: written_mark, 
               comment : comment,
               mark_id : mark_id
              },
        success: function(response)
        {
          if (response.success === true){
            alert("success");
          } else {
            alert('failed');
          }
        },
        error: function(){
          alert("Error");
        },
      });