UPDATE
  tbAppointments
SET
  AppointmentStage = 'Cancelled',
  LastChangeDate = NOW(),
  CancelledDate = CURDATE(),
  CancelledByFullname = @aCancelledByFullname,
  CancelledByReason = @aCancelledByReason,
  CalendarID = 0,
  BillingYearMonth = NULL,
  TimeSpentRate = 0.0,
  TimeSpentTotal = 0.0,
  DistanceTravelledRate = 0.0,
  DistanceTravelledTotal = 0.0,
  TimeTravelledRate = 0.0,
  TimeTravelledTotal = 0.0,
  ServiceValue = 0.0,
  ClientCover = 0.0,
  CoverUsed = 0.0,
  FreeTimeAmount = 0.0,
  FreeHoursUsed = 0.0,
  FreeConsultationUsed = 0.0
WHERE
  AppointmentID = @nAppointmentID