股票计算总和列

Question

我正试图计算股票在SQL中。我有3桌产品，购买和销售。 产品表

+----+------------------+ 
| id | product_name  | 
+----+------------------+ 
| 1 | apple   | 
|----|------------------| 
| 2 |banana   | 
|----|------------------| 
| 3 |mango    | 
+----+------------------+ 

现在颜色表

+----+------------------+ 
| id | color_name  | 
+----+------------------+ 
| 1 | dark   | 
|----|------------------| 
| 2 | light   | 
+----|------------------+ 

购表人是

+-------+-------------+ 
| id | quantity |color 
+-------+-------------+ 
| 1 | 15  |dark 
+-------+-------------+ 
| 1 | 10  |light 
+-------+-------------+ 
| 2 | 5   |dark 
+-------+-------------+ 
| 3 | 25  |light 
+-------+-------------+ 

，销售表

+-------+-------------+ 
| id | quantity |color 
+-------+-------------+ 
| 1 | 5   |dark 
+-------+-------------+ 
| 1 | 5   |light 
+-------+-------------+ 
| 2 | 5   |dark 
+-------+-------------+ 
| 3 | 5   |light 
+-------+-------------+ 

采购和销售表有外键ID参考ences产品表的id。现在我想要计算购买和销售以下形式的现货供应，即区别颜色的基础上，也

+----+------------------+-------------+ 
| id | product_name  | quantity |color 
+----+------------------+-------------+ 
| 1 | apple   | 10  |dark 
|----|------------------|-------------| 
| 1 | apple   | 5  |light 
|----|------------------|-------------| 
| 2 |banana   | 0  |dark 
|----|------------------|-------------| 
| 3 |mango    | 20  |light 
+----+------------------+-------------+ 

Answer 1

您可以找

SELECT p.id,p.Name,Purchase.purchaseQty-sales.salseQty as totalQty 
FROM Product p 
OUTER APPLY(
     SELECT purchase.id, SUM(purchase.quantity) purchaseQty 
     FROM purchase 
     where purchase.id= p.id 
     GROUP BY purchase.id 
)Purchase 
OUTER APPLY(
     SELECT sales.id, SUM(sales.quantity) salseQty 
     FROM sales 
     where sales.id= p.id 
     GROUP BY sales.id 
)sales 

Answer 2

SELECT a.id, a.product_name, 
SUM(b.quantity) - SUM(c.quantity) as 'quantity' 
FROM product a 
LEFT JOIN purchase b 
ON a.id=b.id 
LEFT JOIN sales c 
ON b.id = c.id group by a.id, a.product_name 

（我没有测试任何东西）

Answer 3

试试这个解决方案与外部适用。

drop table if exists dbo.tProduct; 
drop table if exists dbo.tPurchase; 
drop table if exists dbo.tSale; 

create table dbo.tProduct (
    id int 
    , product_name varchar(100) 
); 

create table dbo.tPurchase (
    id int 
    , quantity int 
); 

create table dbo.tSale (
    id int 
    , quantity int 
); 

insert into dbo.tProduct (id, product_name) 
values (1, 'apple'), (2, 'banana'), (3, 'mango'); 

insert into dbo.tPurchase (id, quantity) 
values (1, 15), (2, 10), (1, 5), (3, 25); 

insert into dbo.tSale (id, quantity) 
values (1, 5), (3, 10), (1, 5), (3, 5), (2, 5); 

select 
    p.id 
    , p.product_name 
    , pur.Quantity - sal.Quantity as Quantity 
from dbo.tProduct p 
    outer apply (
     select 
      sum(tp.quantity) as Quantity 
     from dbo.tPurchase tp 
     where p.id = tp.id 
    ) pur 
    outer apply (
     select 
      sum(tp.quantity) as Quantity 
     from dbo.tSale tp 
     where p.id = tp.id 
    ) sal