Export data ke excel dengan php berdasarkan range tanggal

Bantuannya temen", saya ingin export data ke excel per periode sesuai yang user tentukan. - model

     function toExcelAll[] {
        $this->db->select["id_pembelian,tgl_pembelian, total_pembelian"];
        $this->db->from["hpembelian"];
        $getData = $this->db->get[];
        if[$getData->num_rows[] > 0]
        return $getData->result_array[];
        else
        return null;
    } 

- controller

  function toExcelAll[] {
        $query['data1'] = $this->m_laporanpembelian->ToExcelAll[];
        $this->load->view['laporanpembelian/excel',$query];
    } 

- view