Query is not filtering the duplicate rows from two tables in grocery crud, I'm trying to show one list without duplicates and it seems query is being ignored by the controller. What am I doing wrong?

Model

public function delete_duplicaterow()
{ 
    $query = $this->db->query('SELECT intervaloHorario, cita FROM intervaloshorarios JOIN citas '
        . 'ON intervaloshorarios.idIntervaloHorario = citas.idIntervaloHorario '
        . 'GROUP BY intervaloshorarios.intervaloHorario, citas.cita');
    return $query->result();
}

Controller

$this->Fechacita_Model->delete_duplicaterow();

Database