我正在尝试创建一种“摘要”视图,其中应该从几个不同的表([Account]、[Branch]、[Customer]、[Employee]、[Transaction]、[FlaggedTrans])中提取值。
由于我无法在视图中执行大量 SELECT 语句,因此我正在尝试使用 INNER JOIN 完成任务,这就是我的问题所在。
这是我到目前为止所得到的:
CREATE VIEW Summary
AS
SELECT NEWID() AS Summary_Id,
COUNT(C.Customer_Id) AS CustCount,
COUNT(A.Account_Id) AS AcctCount,
COUNT(T.Transaction_Id) AS TransCount,
COUNT(B.Branch_Id) AS BranchCount,
COUNT(E.Employee_Id) AS EmplCount,
CAST(SUM(A.Balance) AS INT) AS BalTotal,
COUNT(F.FlaggedTrans_Id) AS FlagCount
FROM dbo.Account A INNER JOIN
dbo.Customer C ON A.Customer_Id = C.Customer_Id INNER JOIN
dbo.Employee E ON A.Employee_Id = E.Employee_Id INNER JOIN
dbo.[Transaction] T ON A.Account_Id = T.Account_Id INNER JOIN
dbo.FlaggedTrans F ON E.Employee_Id = F.Employee_Id CROSS JOIN
dbo.Branch B
看起来很合乎逻辑,但它导致所有值都返回为 NULL 或 0。我做错了什么?