/**
  * @param array $arrBookingInfo content data to insert to PhieuDatCho collection
  * @param unknown_type $arrBookingDetailInfo content data to insert to ChiTietDatCho collection
  * return true if success and otherwise 
  */
 public function save($arrBookingInfo, $arrBookingDetailInfo)
 {
     // check input
     $arrBookingInfo["NgayLap"] = new MongoDate(strtotime($arrBookingInfo["NgayLap"]));
     // convert date time string to MongoDate
     $temp = array();
     foreach ($arrBookingDetailInfo as $bookingDetailInfo) {
         $bookingDetailInfo["TuThoiGian"] = new MongoDate(strtotime($bookingDetailInfo["TuThoiGian"]));
         $bookingDetailInfo["DenThoiGian"] = new MongoDate(strtotime($bookingDetailInfo["DenThoiGian"]));
         $temp[] = $bookingDetailInfo;
     }
     // insert
     try {
         MongoDatabase::addDataTo("PhieuDatCho", $arrBookingInfo);
         foreach ($temp as $detailInfo) {
             MongoDatabase::addDataTo("ChiTietDatCho", $detailInfo);
         }
         return true;
     } catch (Exception $e) {
         return false;
     }
     return false;
 }
 public function saveIngredientImportingInfo($data)
 {
     return MongoDatabase::addDataTo("PhieuNhapHang", $data);
 }
 /**
  * save bill detail
  * @param array $data
  * @return boolean
  */
 public function saveBillDetail($data)
 {
     return MongoDatabase::addDataTo("ChiTietHoaDon", $data);
 }
 /**
  * add staff to database
  * @param array $data data of staff
  * @return boolean true if success and vice versa.
  */
 public function create($data)
 {
     return MongoDatabase::addDataTo($this::CollectionName, $data);
 }
 public function addStaff($info)
 {
     MongoDatabase::addDataTo("nhanvien", $info);
 }