SQL从两个不同的表中添加和减去数据

Question

我是SQL新手，这是我一生中第一个SQL程序。 我要制作一个具有以下内容的程序：

1. 该表记录了客户一周内交付的负载数量，每个交付负载的费率（费用）以及调度费。
2. 另一个包含费用的表，例如燃料，保险，拖车租金等。
3. 我需要获得一个客户的所有费用的总和，所有费率的总和（每个负载的收入），然后从每个客户的总净工资中减去总费用。

注意：

QuickPay= Rate*0.05
NetPay=Rate-(DispatchFee+QuickPay),
TotalExpenses= Fuel+Advance+Insurance+Trailer
FinalPay=NetPay-TotalExpenses

我已经为每个表创建了一个查询，以进行计算，但是我需要将所有查询合并到一个查询中。 这是查询的代码：

查询TblLInfo

SELECT CustName, sum(Rate) AS RateFee, sum(Disp_Fee) AS DispFee, sum(Rate*0.05) AS QuickPay, sum((Rate)-((Rate*0.05)+(Disp_Fee))) AS NetPay
FROM TblLInfo
GROUP BY CustName;

查询TblExp

SELECT CustName, sum(Fuel) AS FuelFee, sum(Advance) AS AdvanceFee, sum(Insurance) AS InsuranceFee, sum(Trailer) AS TrailerFee, 
sum((Advance)+(Insurance)+(Trailer)+(Fuel)) AS TotalExp
FROM TblExp
GROUP BY CustName;

当我尝试将它们组合时，结果是9（3 * 3）条记录，因为我期望只有3条记录。

[TblLInfo，（表负荷信息），用于收集每周运送一位客户的负荷] [1]

[TblExp（表费用），用于收集每个客户的每周费用] [2]

[查询TblLInfo，以获取特定客户承担的所有负载的总和并减去调度费，这样我们就可以获得净工资] [3]

[查询TblExp，以获取特定客户的总费用] [4]

！[在此处输入图片描述] [1]

！[在此处输入图片描述] [2]

Answer 1

SELECT a.CustName,a.NetPay,b.TotalExp,(b.TotalExp-a.NetPay) AS overall_profit 
FROM
(SELECT CustName, sum(Rate) AS RateFee, sum(Disp_Fee) AS DispFee, sum(Rate*0.05) AS QuickPay, sum((Rate)-((Rate*0.05)+(Disp_Fee))) AS NetPay FROM TblLInfo GROUP BY CustName) a 
INNER JOIN 
(SELECT CustName, sum(Fuel) AS FuelFee, sum(Advance) AS AdvanceFee, sum(Insurance) AS InsuranceFee, sum(Trailer) AS TrailerFee, sum((Advance)+(Insurance)+(Trailer)+(Fuel)) AS TotalExp FROM TblExp GROUP BY CustName)b