sql - 查询添加相同的列条目 WRT 其外键

Question

我有下表，带有属性：

vendor_invoicedetails
   Venid(Pk)
   ven_inv_ref(Fk)
   Item_Code
   Item_Name
   UnitPrice
   VenQuantity

1. 我想将 with 相乘unitPrice以VenQuantity获得我对以下查询所做的总价

   select item_code, 
          VEN_INV_REF, 
          unitprice * ven_itemquantity as total
     from vendor_invoicedetails;
   

2. 我想要的是将TotalPrice两个相同Ven_inv_Ref(Fk)列的总计相加。

在上图中，我想对具有相同VEN_INV_REF编号的条目求和。

Answer 1

试试这个：

DECLARE @datatable TABLE
   (
     ITEM_CODE NVARCHAR(32) PRIMARY KEY CLUSTERED,
     ven_inv_ref NVARCHAR(50),
     Item_Name NVARCHAR(50),
     UnitPrice FLOAT, 
     VenQuantity INT
   )

INSERT INTO @datatable
(ITEM_CODE, ven_inv_ref, UnitPrice, VenQuantity)
VALUES ('battery', 15, 100, 4)

INSERT INTO @datatable
(ITEM_CODE, ven_inv_ref, UnitPrice, VenQuantity)
VALUES ('ABCDE', 16, 200, 4)

INSERT INTO @datatable
(ITEM_CODE, ven_inv_ref, UnitPrice, VenQuantity)
VALUES ('A4', 16, 400, 4)

-- whats in the table   
SELECT * 
FROM @datatable

-- group by reference
SELECT 
    ven_inv_ref, 
    SUM(UnitPrice*VenQuantity) AS totalvalue 
FROM @datatable
GROUP BY ven_inv_ref

结果