SQL Query用于汇总来自不同表的字段

Posted 2021-04-17

我是一个讨厌SQL的谦虚程序员...... :)请帮我解决这个问题。

我有4个表，例如：

Table A:
Id Total
1  100
2  200
3  500

Table B
ExtId  Amount
1      10
1      20
1      13
2      12
2      43
3      43
3      22

Table C
ExtId  Amount
1      10
1      20
1      13
2      12
2      43
3      43
3      22

Table D
ExtId  Amount
1      10
1      20
1      13
2      12
2      43
3      43
3      22

我需要创建一个SELECT，显示表B，C和D的Amount字段的Id，Total和SUM，就像这样

Id Total AmountB AmountC AmountD
1  100   43      43      43
2  200   55      55      55
3  500   65      65      65

我已尝试使用Id对三个表的内部联接并进行金额字段的总和，但结果并不严格。这是错误的查询：

SELECT     dbo.A.Id, dbo.A.Total, SUM(dbo.B.Amount) AS Expr1, SUM(dbo.C.Amount) AS  Expr2, SUM(dbo.D.Amount) AS Expr3
FROM         dbo.A INNER JOIN
                  dbo.B ON dbo.A.Id = dbo.B.ExtId INNER JOIN
                  dbo.C ON dbo.A.Id = dbo.C.ExtId INNER JOIN
                  dbo.D ON dbo.A.Id = dbo.D.ExtId
GROUP BY dbo.A.Id, dbo.A.Total

在此先感谢，它只是我讨厌SQL（或SQL讨厌我）。

编辑：我有一个错字。此查询未提供正确的结果。扩展了这个例子。

答案

或者您可以利用SubQueries：

select A.ID, A.Total, b.SB as AmountB, c.SC as AmountC, d.SD as AmountD
from A
  inner join (select ExtID, sum(Amount) as SB from B group by ExtID) b on A.ID = b.ExtID
  inner join (select ExtID, sum(Amount) as SC from C group by ExtID) c on c.ExtID = A.ID
  inner join (select ExtID, sum(Amount) as SD from D group by ExtID) d on d.ExtID = A.ID

另一答案

从您的描述中，当您在组中使用不存在的列dbo.A.Amount时，此查询应该会给您一个错误。将此更改为dbo.A.Total可能就是您所需要的。

如果您需要所有金额，请尝试以下查询：

select A.Id, A.Total, sum(B.Amount + C.Amount + D.Amount) AS Total_Amount
from A
  inner join B on A.Id = B.ExtId
  inner join C on A.Id = C.ExtId
  inner join D on A.Id = D.ExtId
group by A.Id, A.Total;

另一答案

这个也很好用

SELECT (SELECT SUM(Amount) FROM TableA) AS AmountA, (SELECT SUM(Amount) FROM TableB) AS AmountB, (SELECT SUM(Amount) FROM TableC) AS AmountC, (SELECT SUM(Amount) FROM TableD) AS AmountD

另一答案

这可能有助于其他用户。

SELECT Total=(Select Sum(Amount) from table a)+(Select Sum(Amount) from table b)+(Select Sum(Amount) from table c)

另一答案

尝试此代码SELECT Total = isnull（（从表a）中选择Sum（Isnull（Amount，0）），0）+ isnull（（从表b）中选择Sum（isnull（Amount，0）），0）+ isnull（ （从表c）中选择Sum（isnull（Amount，0）），0）