SQL JOIN- 未被当前用户屏蔽的用户选择

Question

SELECT * FROM User
INNER JOIN BlockUser ON BlockUser.userId='1' and User.userId != BlockUser.blockID

我有两个 table 一个是“Users” table 和 BlockUser table.

我需要 select 来自用户 table 的所有用户，特定用户阻止的用户除外

用户table

userID  userName  nickName
1       abc       abc
2       adc       adc
3       dc        dc
4       xyz       xyz
5       qwe       qwe

阻止用户

_Id  userId  blockID
1      1       2
2      1       3

结果

userID  userName  nickName
4       xyz       xyz
5       qwe       qwe

请帮助我更正我的 Sql 查询。

Answer 1

试试这个：

DECLARE @blocker int = 1
SELECT * FROM [User]
WHERE [User].userID NOT IN (SELECT BlockUser.blockID FROM BlockUser WHERE BlockUser.blockID = [User].userID AND BlockUser.userID = @blocker)
AND userID <> @blocker

http://sqlfiddle.com/#!3/a7012/14

错误也是 SQL 关键字，它是 table 的名称，请更改 table 用户的名称或使用括号，如图所示。

还有其他解决方案（来自其他用户但已删除）：

select u.*
from [User] u
left join BlockUser bu on bu.blockID = u.userID
                      and bu.userId = 1
where bu.userID is null
      and u.userID <> 1;

select * from [user]
where userID <> 1
and userID not in 
  (select blockID from BlockUser 
   where userID = 1);

编辑 1： 固定查询
编辑 2： 搞定了 - 不是 :)
编辑 3： 使用变量
说明从结果中移除拦截器 编辑 4： 添加了其他解决方案

Answer 2

您的查询如下： select userID,userName,nickName from Users where userID NOT IN(Select blockID from BlockUser where userId =1 );

Answer 3

将联接类型更改为外部联接，然后过滤用户 table 以获取非空记录。

Answer 4

select * from user 
where userId <> '1'
and userid not in 
  (select blocked from BlockUser.userId 
   where userId = '1')

SQL JOIN- 未被当前用户屏蔽的用户选择

SQL JOIN- user selection which are not blocked by current user

sql

inner-join