sql 事务

确保语句所有执行成功，如果其中一条不满足，则为失败，进行回滚操作

关键字：tansaction

begin transaction
declare @myerror int=0
UPDATE BankCard SET CardMoney=CardMoney-10000 where CardNo='6225125478544587'
set @myerror=@myerror+@@ERROR
INSERT into CardExchange(CardNo,MoneyInBank,MoneyOutBank,ExchangeTime) values
('6225125478544587',1,0,getdate())
IF @myerror=0
  begin
       COMMIT TRANSACTION
       print '取款成功'
   END
else
   BEGIN
        rollback TRANSACTION
        print '取款失败'
   END