mssql 事务的一个例子

begin tran
                            declare @rownum1 int --未添加订单的空房数
                            declare @rownum2 int --添加订单的空房数目
                            declare @BookID1 int
                                set @BookID1=0
                            insert into T_BookRoomInfo(RoomID,CustomerName,CustomerCardID,Discount,
                                  EnterTime,DepositMoney,Memo,UserID,UpdTime)
                            values (@RoomID,@CustomerName,@CustomerCardID,@Discount,
                                   getdate(),@DepositMoney,@Memo,@UserID,getdate())
                            select @BookID1=@@IDENTITY
                            if(@BookID1<>0)
                                begin
                                       select @rownum1=count(1)
                                         from T_Room
                                        where IsEmploy=0
                                update T_Room
                                set IsEmploy=1
                                where RoomID=@RoomID
                                       select @rownum1=count(1)
                                         from T_Room
                                        where IsEmploy=0

                                if(@rownum1<=@rownum2)
                                    begin 
                                        rollback tran
                                    end
                                else
                                    begin 
                                        commit tran        
                                    end
                                end
                            else
                                    begin 
                                         rollback tran        
                                    end