sql - 来自两个不同表的 SQL SUM

Question

我正在尝试构建一个 SQL Sum 语句来汇总来自不同表的数据。每个表都有一个共同的 SalesRep 字段。我在弄清楚如何正确构建 SQL 时遇到了一些麻烦。

我知道下面的语法是错误的并且不起作用，但我不是 SQL 专家。我确定这很简单。有人能帮助我吗？

SELECT SalesRepID, SUM(SELECT SalesRepID, Sum(tblClientAdditions.Amount) AS Subtotal
FROM tblClientAdditions GROUP BY SalesRepID + SELECT SalesRepID, 
Sum(tblAccounts.ReceivedAmount) AS Subtotal1
FROM tblAccounts GROUP BY SalesRepID) FROM tblSalesReps;

Answer 1

表之间没有关系，对吧？

比可能是这样的吗？

SELECT (SELECT SUM(value) FROM table1) + (SELECT SUM(value) FROM table2) as result

问候

Answer 2

SELECT SalesRepID, 

(SELECT Sum(tblClientAdditions.Amount) FROM tblClientAdditions 
where tblClientAdditions.SalesRepID =tblSalesReps.SalesRepID)
+
(SELECT Sum(tblAccounts.ReceivedAmount) FROM tblAccounts
where tblAccounts.SalesRepID =tblSalesReps.SalesRepID)

FROM tblSalesReps;

Answer 3

我添加了 IsNull ，因为如果其中一列为空，您将在答案中得到空值，而您不希望这样。

SELECT ISNull(SUM(Table1.column1),0)+ (SELECT ISNull(SUM(Table2.column1),0) FROM Table2) FROM Table1 

这对我有用。