I am uploading a file and the size remains as 0 in the database

$djenjang_capaian = $this->session->userdata('djenjang_capaian'); $pengirim = $this->session->userdata('pengirim'); $path = FCPATH. "/upload/document/capaian/$pengirim"; if(!is_dir($path)) { mkdir($path,0777,TRUE); } $config['upload_path'] = $path; $config['allowed_types'] = 'jpg|png|pdf|xlsx|xls|doc|docx|zip|rar'; $config['max_size'] = "2048"; $file_name = "dok-cpn-" . rand(100, 999) . uniqid(); $config['file_name'] = $file_name; $this->load->library('upload', $config); $this->upload->do_upload('dokumen_file'); $dokumen = $this->upload->data('file_name'); $dokumen_file = $dokumen; $ukuran_file = $dokumen_file['size']; $data = array( 'dokumen_file' => $dokumen_file, 'ukuran_file' => $ukuran_file ); if ($this->db->insert($djenjang_capaian, $data)) { $this->session->set_flashdata("success", " Data berhasil ditambahkan!"); redirect('user/page/pemenuhan_dokumen'); } else { $this->session->set_flashdata("error", " Data gagal ditambahkan!"); redirect('user/page/pemenuhan_dokumen'); }

This code runs fine but keeps inserting 0's on the ukuran_file field. How to insert file size into database? ...