update another column if another column got post (Codeigniter) PHP - php

Question

I have this simple code that display only 2 column (step and feedback)
so whenever the "feedback" has submited or post like in my controller below and the "step" column would count like $step+=1 or update with query update my_table set step = step + 1 where id = $user_id ,,which is if "feedback" has submited the "step" column always increment ++ .
controllers/Person.php
public function ajax_update()
{
$data = array(
//'step' => $this->input->post('step'),
'feedback' => $this->input->post('feedback'),
);
$this->person->update(array('user_id' => $this->input->post('user_id')), $data);
echo json_encode(["status" => TRUE]);
}
Model/Person_model.php
public function update($where, $data)
{
$this->db->update($this->table, $data, $where);
return $this->db->affected_rows();
}
Views/person_view.php
<div class="form-group">
<label class="control-label col-md-3">kcp naem</label>
<div class="col-md-9">
<input name="feedback" placeholder="status" class="form-control" type="text">
<span class="help-block"></span>
</div>
</div>
<button type="button" id="btnSave" onclick="save()" class="btn btn-primary">Save</button>
plus jquery ajax for button save()
function save()
{
$('#btnSave').text('saving...'); //change button text
$('#btnSave').attr('disabled',true); //set button disable
var url;
url = "<?php echo site_url('person/ajax_update')?>";
// ajax adding data to database
$.ajax({
url : url,
type: "POST",
data: $('#form').serialize(),
dataType: "JSON",
success: function(data)
});
}
maybe we should just focus on the controller and model .
Some assistance would be great on how to setup the update.
Thankyou

Answer 1

You can do this in qb using the following method:
$this->db->set('step', 'step+1', FALSE);
$this->db->where('user_id', $user_id);
$this->db->update('tablename');
https://www.codeigniter.com/userguide3/database/query_builder.html#updating-data
// controller
public function ajax_update() {
$feedback = $this->input->post('feedback');
$uid = $this->input->post('user_id');
if (!is_null($feedback) && !is_null($uid)) {
// only increment: "whenever the "feedback" has submited or post"
$this->person->update_feedback($uid, $feedback);
echo json_encode(["status" => TRUE]);
} else {
echo json_encode(['status' => FALSE]); //?
}
}
// model
public function update_feedback($user_id, $feedback) {
$this->db->set('step', 'step+1', FALSE);
$this->db->set('feedback', $feedback);
$this->db->where('user_id', $user_id);
$this->db->update($this->table);
return $this->db->affected_rows();
}