Codeigniter: You must use the "set" method to update an entry
<p>I am trying to insert data using a submitted form. Data is entered properly in the database, but I'm doing API also for mobile. If <code>is_api</code> parameter is received, I'm doing <code>jsone_encode</code>. The following is the code:</p>

<p><strong>Controller:</strong></p>

<pre><code>public function send_request(){
            if($this-&gt;input-&gt;post('submit')){        
                $user_data['data'] = array( 
                    'user_id'                =&gt;  1,
                    'sender_name'            =&gt;     $this-&gt;input-&gt;post('sender_name'),
                    'sender_location'        =&gt;     $this-&gt;input-&gt;post('sender_location'),
                    'sender_mobile'          =&gt;     $this-&gt;input-&gt;post('sender_mobile'),
                    'receiver_name'          =&gt;     $this-&gt;input-&gt;post('reciever_name'),
                    'receiver_location'      =&gt;     $this-&gt;input-&gt;post('reciver_location'),
                    'receiver_mobile'        =&gt;     $this-&gt;input-&gt;post('reciver_location'),
                    'request_type'           =&gt;     $this-&gt;input-&gt;post('request_type'),
                    'is_urget'              =&gt;     0,
                );

            }
            $result = $this-&gt;user_model-&gt;send_request($user_data);
             if($result){
                $this-&gt;result_set['message'] = 'Data entered ';
                $this-&gt;result_set['status']= 1;
             }
                if( $this-&gt;input-&gt;post('is_api') == 1){
                    echo json_encode($this-&gt;result_set);
                    die();
                }
         }
</code></pre>

<p><strong>Model:</strong> </p>

<pre><code>public function send_request($data){
        $this-&gt;db-&gt;insert('parcel_requests',$data['data']);
        return true;
     }
</code></pre>

<p>When I check <code>hurl.it</code> for API, I get this error and response:</p>

<blockquote>
  <p><h1>A Database Error Occurred</h1>
        <p>You must use the "set" method to update an entry.</p>
        <p>Filename: /home/foldername/public_html/parcel/models/user_model.php</p>
        <p>Line Number: 21</p></p>
</blockquote>

<p>This is line number 21:</p>

<pre><code>    $this-&gt;db-&gt;insert('parcel_requests',$data['data']);
</code></pre>

<p>Now data is entered properly, but <em>not converted to json</em>. I need your help to sort out this issue, thanks!</p>