How to get the latest inserted table id in codeigniter?

Question

I have this function in my controller, this is used for insert data to database mysql.

    public function tambah() 
{
    $data = array(
        'elektronik_nama' => $this->input->post('elektronik_nama'),
        'elektronik_kode' => $this->input->post('elektronik_kode'),
        'elektronik_merk' => $this->input->post('elektronik_merk'),
        'elektronik_lokasi' => $this->input->post('elektronik_lokasi'),
        'elektronik_tahun_pengadaan' => $this->input->post('elektronik_tahun_pengadaan'),
        'elektronik_sbr_perolehan' => $this->input->post('elektronik_sbr_perolehan'),
        'elektronik_kondisi' => $this->input->post('elektronik_kondisi'),
        'elektronik_harga' => $this->input->post('elektronik_harga'),
    );

    $data_tronik = $this->in_elektronik_model->tambah_data($data);

    $data_tronik_mebel = array(
        'semua_aset_id_aset' => $data_tronik,
        'semua_aset_nama' => $this->input->post('elektronik_nama'),
        'semua_aset_kode' => $this->input->post('elektronik_kode'),
    );

    $this->in_semua_aset_model->tambah_data($data_tronik_mebel);
}

and i have two models to insert data

    class In_elektronik_model extends CI_Model {

       function tambah_data($data)
       {
           $this->db->insert('in_elektronik',$data);
       }
  }

and

class In_semua_aset_model extends CI_Model {

    function tambah_data($data) 
   {
        $this->db->insert('in_semua_aset', $data);
   }
}

i assumed that 'semua_aset_id_aset' => $data_tronik, will give primary key from in_elektronik_model, but the result give NULL to in_semua_aset_model. How to get primary key from in_elektronik_model?

Answer 1

Is the primary key the insert id? In that case:

class In_elektronik_model extends CI_Model {

     function tambah_data($data)
    {
         $this->db->insert('in_elektronik',$data);
         $inserted_id = $this->db->insert_id();
         return $inserted_id;
    }
}