update multiple rows after insert in codeigniter - codeigniter

Question

After insert I want to update field with ($id.'mytext') where in db that field is empty for all rows.
table name: peca
columns:
id -autoincrement
A -varchar user insert
CB -varchar auto insert with update
MODEL WILL RETURN ALL ROWS WHERE CB=empty
function model1() {
$this->db->select('*');
$this->db->from('peca');
$this->db->where('CB', '');
//$this->db->where('id', $fileid);
$query = $this->db->get();
if ($query) {
return $query->result();
} else {
return false;
}
}
MODEL WILL update in db where CB=empty
function model2($dados = NULL) {
if ($dados !== NULL) {
// extract($dados);
$this->db->where('CB', '');
$this->db->update('peca', $dados);
return true;
} else {
return false;
}
}
CONTROLLER
$this->load->model('model_peca');
$resultadocadastropeca = $this->model_peca->model1($id);
$data = 'id' => $id;
$appointment = array('codigoean' => $data.'.PECA.');
$appointment = $this->model_peca->model2($appointment);
START TABLE
Previous values inserted from import so CB can only be generated after id exists
id|CB |
22| |
31| |
RESULTS
I'm changing CB to .PECA. in all rows where CB=empty but $id for each row is not passing
id|CB |
22|.PECA.|
31|.PECA.|
EXPECTED
id|CB |
22|22.PECA.|
31|31.PECA.|

Answer 1

I still don't fully understand what you want to do, but if you want to fetch something where a column is empty or null:
$this->db->where("WHERE yourColumn IS NULL OR yourColumn = ''");
As per your revised question, this should work:
$this->db->select('id');
$this->db->where('CB', '');
$q = $this->db->get('peca');
if ($q->num_rows() == 0) {
die('nothing to do here');
}
$res = $q->result();
foreach ($res as $item) {
$data[] = array('id' => $item->id, 'CB' => $item->id . '.PECA.');
}
$this->db->update_batch('peca', $data, 'id');