基本查询的聚合函数错误

Question

我的数据库是基于电影院的，我正在尝试进行查询以显示每次电影放映所购买的门票数量。该查询涉及的table是Bookings、Screenings和Movies.

这是预订 table:

放映table:

和电影 table:

到目前为止，我已经设法将查询查询到能够显示每次放映的预订量的程度，但这并没有考虑到一个事实可能是购买了多张票单次预订，因此 预订数量:

中的数量列

这是让我走到这一步的 SQL 代码：

SELECT Count(Bookings.[Booking ID]) 
AS [Bookings Per Screening], 
Bookings.[Screening ID], 
Movies.Movie 
FROM Movies 
INNER JOIN (Screenings 
INNER JOIN Bookings 
ON 
Screenings.[Screening ID] = Bookings.[Screening ID]) 
ON Movies.[Movie ID] = Screenings.[Movie ID] 
GROUP BY 
Bookings.[Screening ID], Movies.Movie, 
Screenings.[Movie ID], Movies.[Movie ID];

但是当我尝试添加一个字段来计算每次放映购买的门票数量，而不是每次放映的预订量时，每次放映都会显示多行：

这是生成该代码的代码：

SELECT Count(Bookings.[Booking ID]) 
AS [Bookings Per Screening], 
Bookings.[Screening ID], 
Movies.Movie, 
[Bookings Per Screening]*[Quantity] AS [Ticket Per Booking], 
Bookings.Quantity
FROM Movies 
INNER JOIN (Screenings 
INNER JOIN Bookings 
ON Screenings.[Screening ID] = Bookings.[Screening ID]) 
ON Movies.[Movie ID] = Screenings.[Movie ID]
GROUP BY Bookings.[Screening ID], Movies.Movie, 
Screenings.[Movie ID], Movies.[Movie ID], Bookings.Quantity;

我必须做什么才能让它工作？

Answer 1

Movies.Quantity 和 SELECT 语句中的 [每次放映预订]*[数量] AS [每次放映门票] 之间似乎缺少 ,。

Answer 2

停止计算预订并乘以它们。

每一行都已经告诉你售出了多少票。

SELECT
  [Screenings].[Screening Date],
  [Screenings].[Screening Time],
  [Movie].[Movie],
  SUM([Bookings].[Quantity]) AS [Seats Bought]
FROM
  [Bookings]
INNER JOIN
  [Screenings]
ON [Bookings].[Screening ID] = [Screenings].[Screening ID]
INNER JOIN
   [Movies]
ON  [Movies].[Movie ID] = [Screenings].[Movie ID]
GROUP BY
  [Screenings].[Screening Date],
  [Screenings].[Screening Time],
  [Movie].[Movie];

基本查询的聚合函数错误

Aggregate Function Error With Basic Query

sql

ms-access

group-by

inner-join

relational-database