Question

我正在查询3张赌桌，费用和收入：

SELECT c.CarMake, c.CarType, 
(SUM(i.IncomeKMEnd -i.IncomeKMStart)) AS TotalKms,
MAX(i.IncomeKMEnd) as EndingKMs,
CONVERT(varchar(10), CONVERT(int,100.0*(SUM(i.IncomePrice) - SUM(e.ExpenseAmount))/c.CarBuyPrice)) +'%' as IncomePercentage, 
SUM(CASE WHEN e.PaymentType LIKE '%extra%' THEN e.ExpenseAmount ELSE 0 END) AS     ExpenseSum

FROM (Cars AS c  
INNER JOIN Incomes as i ON c.CarID = i.CarID AND (i.IncomeDateFrom BETWEEN '20130101' AND '20140101')) 
INNER JOIN Expenses as e ON i.CarID = e.CarID AND (e.ExpenseDateFrom BETWEEN '20130101' AND '20140101') 

GROUP BY c.CarType, c.CarMake, c.CarBuyPrice

在Cars表中有一辆车，它在Incomes表中被反映了3次，在Expenses表中有2次。未分组时，此查询返回6行，并将费用和收入相加6次。有没有办法让它正确地计算收入和支出？

Answer 1

执行此操作的一种方法是不加入另一个表，而是将子信息中的信息拉出来。例如：

SELECT c.CarMake, c.CarType,
 (SELECT SUM(IncomePrice) FROM Incomes WHERE CarID = c.CarID and (IncomeDateFrom BETWEEN '20130101' AND '20140101')) SumPrice
FROM Cars AS c

Answer 2

如果您使用的是SQL Server 2005或更新版本，那么最好使用APPLY子句。此外，我认为你应该考虑到特定CarId的收入和支出是空的。

SELECT  c.CarMake, 
    c.CarType, 
    i.TotalKms,
    i.EndingKMs,
    CONVERT(varchar(10), CONVERT(int,100.0*( isnull( i.IncomePriceTotal, 0) - isnull( e.ExpenseAmountTotal, )) / c.CarBuyPrice)) +'%' as IncomePercentage, 
    e.ExpenseSum
FROM Cars c
OUTER APPLY
(
    SELECT  SUM(i.IncomeKMEnd -i.IncomeKMStart) AS TotalKms,
            MAX(i.IncomeKMEnd) as EndingKMs,
            SUM(i.IncomePrice) as IncomePriceTotal
FROM Incomes i 
WHERE i.CarID = c.CarID 
AND i.IncomeDateFrom BETWEEN '20130101' AND '20140101'
) i
OUTER APPLY
(
SELECT  SUM(e.ExpenseAmount) as ExpenseAmountTotal, 
        SUM(CASE WHEN e.PaymentType LIKE '%extra%' THEN e.ExpenseAmount ELSE 0 END) AS ExpenseSum
FROM Expenses e 
WHERE e.CarID = c.CarID 
AND e.ExpenseDateFrom BETWEEN '20130101' AND '20140101'
) e

查询返回重复行的三个表

2 个答案: