Question

表和列位于

之下

VSTest   C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\CommonExtensions\Microsoft\TestWindow

我想选择总库存最多的自行车，即自行车店的品牌+库存？我该怎么做呢？这是我到目前为止所没有执行的。

Bikers(BikerName, Country, Age, Category, World_Cup_Wins, 

World_Championship_Wins, Brand, Bike)

BikerMeetUp(BikerName, Date, Location)

BikeShopInfo(BikeShopName, Telephone_Number, Address, Website)

Brands(BrandName, Website, Model)

Bikes(Model, Price, Weight, Colour, Rating, State)

BikeTyre(Model, Tyre_Model, Size)

BikeForks(Model, Fork_Model, Travel)

BikeBrandSellStock(Model, Size, BrandStock)

BikeShopSellBike(BikeShopName, Model, Size, BikeShopStock)

Answer 1

也许你过度思考它：

SELECT * 

FROM 
 bikebrandsellstock b 
 INNER JOIN 
 bikeshopsellbike s 
 ON s.model = b.model and s.size = s.size

ORDER BY b.brandstock + s.bikeshopstock DESC
LIMIT 1

Answer 2

(SELECT MAX(SUM(bikebrandsellstock.stock+bikeshopsellbike.stock)))中的语法不正确，您错过了FROM语句。

Answer 3

SELECT model
     , SUM(stock) total
  FROM
     ( SELECT Model, BrandStock stock FROM BikeBrandSellStock
        UNION
       SELECT Model, BikeShopStock FROM BikeShopSellBike
     ) x
 GROUP
    BY model
 ORDER 
    BY total DESC 
 LIMIT 1;

此解决方案不考虑关系。

我该如何做这个选择语句？

3 个答案: