Sql server 编写查询以选择给定特定条件的特定外键条目

因此，我有一个表，其中FK代表UserId，FK代表ProductId

如果每个用户ID有多个产品，则可以多次列出

我需要查询以获取每个用户标识，例如，productID1，但productID2

我如何开始编写这样的查询

编辑：

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但这是我遇到问题的部分；所有拥有产品1的用户都应该拥有产品2，但有些用户没有，因此我需要获得拥有产品1而不是产品2的用户-这是您想要的吗

select distinct userID from yourtable t
where t.ProductId=@ProductID1
and not exists(select UserID from yourtable 
                      where Userid=t.userID and ProductID=@ProductID2)

SELECT 
    u.[UserID]
  , p.[ProductID]
FROM TableA a
    LEFT JOIN Users u ON
        u.[UserID] = a.[UserID]
    LEFT JOIN Products p ON
        p.[ProductID] = a.[ProductID]
WHERE a.ProductID = 1

---

-这是你想要的吗

SELECT 
    u.[UserID]
  , p.[ProductID]
FROM TableA a
    LEFT JOIN Users u ON
        u.[UserID] = a.[UserID]
    LEFT JOIN Products p ON
        p.[ProductID] = a.[ProductID]
WHERE a.ProductID = 1

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假设您在用户和产品之间有一个桥接表

如果你想要的比身份证还多

SELECT u.user_id, u.name
FROM [user] AS u
INNER JOIN user_product AS up 
        ON u.user_id = up.user_id
INNER JOIN product as p 
        ON p.product_id = up.product_id
WHERE p.id = 1

或者您可以只查询您的桥接表

SELECT up.user_id
FROM user_product AS up
WHERE up.product_id = 1

---

假设您在用户和产品之间有一个桥接表

如果你想要的比身份证还多

SELECT u.user_id, u.name
FROM [user] AS u
INNER JOIN user_product AS up 
        ON u.user_id = up.user_id
INNER JOIN product as p 
        ON p.product_id = up.product_id
WHERE p.id = 1

或者您可以只查询您的桥接表

SELECT up.user_id
FROM user_product AS up
WHERE up.product_id = 1