Question

我的数据库中有两个表销售和设备：

销售

SaleDate   EmployeeID AppID Qty
---------- ---------- ----- -----------
2010-01-01 1412       150   1
2010-01-05 3231       110   1
2010-01-03 2920       110   2
2010-01-13 1412       100   1
2010-01-25 1235       150   2
2010-01-22 1235       100   2
2010-01-12 2920       150   3
2010-01-14 3231       100   1
2010-01-15 1235       300   1
2010-01-03 2920       200   2
2010-01-31 2920       310   1
2010-01-05 1412       420   1
2010-01-15 3231       400   2

电器设备

ID   AppType              StoreID Cost          Price
---- -------------------- ------- ------------- -------------
100  Refrigerator         22      150           250
110  Refrigerator         20      175           300
150  Television           27      225           340
200  Microwave Oven       22      120           180
300  Washer               27      200           325
310  Washer               22      280           400
400  Dryer                20      150           220
420  Dryer                22      240           360

如何获取此结果表。（列出了冰箱和每次销售的销售数量，也显示了总销售价格（总销售价格=数量*价格）。

AppID AppType          Qty         total sale price
----- ---------------- ----------- ----------------
110   Refrigerator     1           300
110   Refrigerator     2           600
100   Refrigerator     1           250
100   Refrigerator     2           500
100   Refrigerator     1           250

我的尝试：

SELECT AppID, AppType, Qty, (Qty * Price) as 'total sale price'
FROM Sales s, Appliances a
WHERE (AppID) IN (SELECT ID FROM Appliances WHERE AppType = 'Refrigerator')
AND (AppType) IN ('Refrigerator')

目前正在制作

AppID AppType              Qty         total sale price
----- -------------------- ----------- ----------------
110   Refrigerator         1           250
110   Refrigerator         1           300
110   Refrigerator         2           500
110   Refrigerator         2           600
100   Refrigerator         1           250
100   Refrigerator         1           300
100   Refrigerator         2           500
100   Refrigerator         2           600
100   Refrigerator         1           250
100   Refrigerator         1           300

Answer 1

在join

上执行sales.AppId = appliances.ID

select s.AppId, a.AppType, s.Qty, 
   a.Price * s.Qty as total
from appliances a
join sales s on s.AppId = a.ID
where a.AppType = 'Refrigerator'

Answer 2

您可以使用JOIN：

执行此操作

ONLINE DEMO

SELECT
    AppID   = p.ID,
    p.AppType,
    s.Qty,
    [Total Sales Price] = s.Qty * p.Price
FROM Sales s
INNER JOIN Appliances p
    ON p.ID = s.AppID
WHERE p.AppType = 'Refrigerator'

请注意

您需要avoid using the old-style JOIN syntax并改为使用JOIN关键字。

如何从两个表中正确选择（SQL）

2 个答案: