Question

我有这个复杂的（对我而言）要求，并希望得到一个SQL查询。这是交易：

这个表在Access文件中名为“Expenses”。
该表包含“类别”，“金额”，“付款人”和“IsShare”等字段。
类别可以是煤气，杂货，家居等......
金额是费用的美元金额。
付款人可以是我或我的兄弟（“我”或“兄弟”）。
IsShare可以是真的也可以是假的。基本上如果IsShare是真的，则费用分为两部分。否则，付款人会支付全部费用。

我需要一个SQL查询来计算特定类别的所有费用。它应该这样计算：

我支付的所有非共享项目的100％（Payer ='Me'和IsShare = false），
我支付的所有共享项目的50％（Payer ='Me'和IsShare = true），
我哥哥支付的所有共享项目的50％（Payer ='Bro'和IsShare = true）。

查询应该返回所有这三个项的总和。

到目前为止，我有一个初步查询，但它返回不正确的结果。有人能为我纠正吗？

非常感谢。

return @"SELECT Sum(Amount) AS TotalAmount " +
        "FROM Expenses " +
        "WHERE Category = 'Groceries' " +
        "AND Payer = 'Me' " +
        "AND Share = false " +
        "GROUP BY Category " +
        "UNION " +
        "SELECT 0.5 * Sum(Amount) AS TotalAmount " +
        "FROM Expenses " +
        "WHERE Category = 'Groceries' " +
        "AND Payer = 'Me' " +
        "AND Share = true " +
        "GROUP BY Category " +
        "UNION " +
        "SELECT 0.5 * Sum(Amount) AS TotalAmount " +
        "FROM Expenses " +
        "WHERE Category = 'Groceries' " +
        "AND Payer = 'Bro' " +
        "AND Share = true ";
        "GROUP BY Category";

Answer 1

我认为你想要做的事情不需要UNION。这将传递一次数据并将值放在各列中。您可能需要将0.5转换或转换为特定类型，我没有机会运行它。

SELECT 
     Category,
     SUM(CASE WHEN Payer='me' AND NOT IsShare THEN Amount ELSE 0 END) as IPaid,
     SUM(CASE WHEN Payer='me' AND IsShare THEN Amount * 0.5 ELSE 0 END) as SharedPay,
     SUM(CASE WHEN Payer='bro' AND IsShare THEN Amount * 0.5 ELSE 0 END) as BrotherPay
FROM Eexpenses
WHERE Category = 'Groceries'
GROUP BY Category

对于MS ACCESS：

SELECT 
     Category,
     SUM(IIF(Payer='me' AND NOT IsShare, Amount,0)) as IPaid,
     SUM(IIF(Payer='me' AND IsShare, Amount * 0.5, 0)) as SharedPay,
     SUM(IIF(Payer='bro' AND IsShare, Amount * 0.5, 0)) as BrotherPay
FROM Eexpenses
WHERE Category = 'Groceries'
GROUP BY Category

将三列一起添加：

SELECT Category, IPaid, SharedPay, BrotherPay, IPay + SharedPay + BotherPay as Total 
FROM (
    SELECT 
         Category,
         SUM(IIF(Payer='me' AND NOT IsShare, Amount,0)) as IPaid,
         SUM(IIF(Payer='me' AND IsShare, Amount * 0.5, 0)) as SharedPay,
         SUM(IIF(Payer='bro' AND IsShare, Amount * 0.5, 0)) as BrotherPay
    FROM Eexpenses
    WHERE Category = 'Groceries'
    GROUP BY Category
) as T1

一个（稍微复杂）的SQL查询？

1 个答案: