要基于创建的变量在SQL Server中合并查询

Question

select SalesOrderDetailID, CustomerID, A.SalesOrderID, Round(UnitPrice * OrderQty, 2) as TotalCost FROM SalesLT.SalesOrderHeader A 
    Left Outer Join SalesLT.SalesOrderDetail B
        ON A.SalesOrderID = B.SalesOrderID
Order by SalesOrderDetailID

因此，我想对其进行合并，以便只有唯一的客户ID，并且可以为每个客户ID汇总TotalCost，如何仅通过查询交互来做到这一点？

Answer 1

所以我想对其进行合并，这样我只有唯一的客户ID，并且可以为每个客户ID汇总TotalCost，

您似乎正在寻找聚合：]​​>

Select 
    s.CustomerID, 
    Round(sum(d.UnitPrice * d.OrderQty), 2) as TotalCost 
From SalesLT.SalesOrderHeader s
Left Outer Join SalesLT.SalesOrderDetail d On d.SalesOrderID = s.SalesOrderID
Group by s.CustomerID
Order by s.CustomerID
这将为您提供每位客户一条记录及其总费用。