CREATE OR ALTER TRIGGER AU_CONTRACT_EXTRA FOR CONTRACT_EXTRA
ACTIVE AFTER UPDATE POSITION 0
AS
begin
  if (((new.EXECUTE_BEGIN <> old.EXECUTE_BEGIN)
    or (old.EXECUTE_BEGIN is null))
    or ((new.EXECUTE_END <> old.EXECUTE_END)
    or (old.EXECUTE_END is null))) then
    execute procedure SP_PROPOSAL_ADD_TO_CONTRACT(-1, old.CONTRACT_ID, 2);
end