Question

我有一个任务，我必须使用SQL创建发票，我在第一次尝试内部连接时遇到了问题，并且对所有这些都非常新。当尝试乘以创建的别名时，它会引发错误：

＃1054 - “字段列表”中的未知列'Bookings.CostumeID'

我不知道我做错了什么，前两个别名到目前为止工作正常。任何帮助表示赞赏！

代码低于

SELECT booking.BookingID, booking.CustID, Bookings.CostumeID, booking.DateIn,
booking.DateOut, booking.DateDue, customer.Fname, customer.Sname, costume.Description,

DateIn-DateOut AS TotalDays,
DateIn-DateDue AS LateDays,
LateDays*10 AS Penalty

FROM booking
INNER JOIN customer ON booking.CustID = customer.CustID
INNER JOIN costume ON booking.CostID = costume.CostID
where BookingID=1

Answer 1

你错误地使用了Bookings.CostumeID。

使用booking.CostumeID代替Bookings.CostumeID

尝试此查询

SELECT booking.BookingID, booking.CustID, booking.CostumeID, booking.DateIn,
booking.DateOut, booking.DateDue, customer.Fname, customer.Sname, costume.Description,

DateIn-DateOut AS TotalDays,
DateIn-DateDue AS LateDays,
(DateIn-DateDue)*10 AS Penalty

FROM booking
INNER JOIN customer ON booking.CustID = customer.CustID
INNER JOIN costume ON booking.CostID = costume.CostID
where BookingID=1

在SQL中乘以别名

1 个答案: