Question

我有3个表以下，我想编写一个SQL查询，列出所有城市的商店:(这里的结果应该是“沃尔玛”）

Stores:
ID  Name
1   Walmart
2   Target
3   Sears

Stores_City
ID  Store_id     City ID
1   1            10
2   1            20
3   2            10
4   1            30


City
ID  Name
10  NewYork
20  Boston
30  Eagan

我无法找到有效的查询。任何帮助表示赞赏！

Answer 1

select s.Name
from Stores s 
inner join
(
select store_id, count(distinct city_id)
from stores_city
group by store_id
having count(distinct city_id) = (select count(*) from City)
) x
on x.store_id = s.id;

您可以通过对store_id进行分组并检查商店中的计数表来执行此操作。

Answer 2

直接加入可行

在s.id = sc.id上从商店的内部联盟商店_city SC中选择不同的s.name 内部加入城市c Sc.city_id = c.id

Answer 3

这是另一种方法：

select s.*
from stores s
where not exists (
  select c.id
  from city c
  except
  select sc.city_id
  from stores_city sc
  where sc.store_id = s.id
)

Answer 4

试试这个：

SELECT
    s.Name
FROM Stores s
WHERE NOT EXISTS (SELECT TOP 1
    1
FROM City c
LEFT JOIN Stores_City sc
    ON c.ID = sc.CityID
    AND sc.Store_id = s.ID
WHERE sc.ID IS NULL)

SQL查询以查找在另一个表

4 个答案: