SQL查询来过滤多对多关系

Question

我有这个表的多对多的关系

USER 
----- 
Id 


CASE 
---- 
Id 
Created 

Users_Cases 
------------ 
UserId 
CaseId 

你能帮我找出SQL查询来获取谁的情况下，在某个日期之前创建的用户（ 2015年10月14日）？谢谢，

编辑：如果用户有2例，第一种情况是日期和日期后，在另一个之前创建的使用不应该被包括在结果

User 
User1 
User2 
User3 

Case 
Case1 - 9/14/2015 
Case2 - 11/14/2015 
Case3 - 12/14/2015 
Case4 - 8/15/2015 

Users_Cases 
User1 - Case1 
User1 - Case2 
User2 - Case3 
User3 - Case4 

预期的结果：只有用户3。用户1的日期为<，但还有另一种情况> =日期，因此user1未包含在结果中。

Answer 1

SELECT * 
FROM "user" u 
INNER JOIN "Users_Cases" uc ON u.id = uc.UserId 
INNER JOIN "CASE" c ON uc.CaseId = c.id WHERE c.Created < '10/14/2015' 

OR

SELECT * 
FROM "user" 
WHERE id IN (
     SELECT UserId 
     FROM "Users_Cases" uc 
     INNER JOIN "CASE" c ON uc.CaseId = c.id WHERE c.Created < '10/14/2015') 
     ) 

---

编辑：由于每个操作的评论

SELECT * 
FROM "user" 
WHERE id IN (
     SELECT uc.UserId 
     FROM "case" c 
     INNER JOIN "Users_Cases" uc ON uc.CaseId = c.id 
     WHERE c.Created < '10/14/2015' 
     ) 

Answer 2

可能这应该工作，因为我认为你要排除谁创造情况下，这些用户在指定的日期之后。

Select * from User as A 
    inner join UserCases as B on A.ID = B.UserID 
    inner join case as C on B.CaseID = C.ID 
Where C.Created <= @GivenDate 
    and A.ID not in (Select UserID from User_cases as D 
       inner join case as E on D.CaseID = E.ID 
       Where E.Created >= @GivenDate 
      ) 

如果您只想要一个ID，请使用group by子句。

Select A.ID from User as A 
    inner join UserCases as B on A.ID = B.UserID 
    inner join case as C on B.CaseID = C.ID 
Where C.Created <= @GivenDate 
    and A.ID not in (Select UserID from User_cases as D 
       inner join case as E on D.CaseID = E.ID 
       Where E.Created >= @GivenDate 
      ) 
group by A.ID 

Answer 3

SELECT U.* 
FROM `USER` AS U 
WHERE EXISTS (SELECT 1 FROM `Users_Cases` AS UC 
      INNER JOIN `case` AS C ON UC.CaseId=C.`id` 
      WHERE UC.UserId=U.`id` 
      AND C.`Created`<'2015-10-14' 
)