Question

我试图从表A中获取表B中不存在的具有特定MeetingID的所有用户名就像iam试图获得Meetingid：2，表A应该返回用户测试并将其余部分保留。 MeetingID 6返回Test。这可以用一个查询吗？

表A： ID，用户名1测试2测试3 Testood

表B： Meetingid，用户名2测试2 Testood 6测试6 Testood

这是我一直努力工作的代码：

SELECT members.username FROM members RIGHT JOIN attendmeeting ON
attendmeeting.username=members.username WHERE attendmeeting.username
NOT LIKE members.username ORDER BY username DESC

表A是成员，表B是出席会议。我不知道如何基于会议ID来过滤掉它。

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编辑：感谢Harsh Gupta，第一部分现在正在运作。最后一件事是仅使用与这些成员的特定会议ID来过滤掉NOT LIKE。

当前代码：

SELECT members.username 
FROM members 
LEFT JOIN attendmeeting 
ON attendmeeting.username = members.username 
WHERE attendmeeting.username IS NULL 
ORDER BY members.username DESC

Answer 1

我不确定你的tableA和tableB是哪个：

SELECT members.username 
FROM members 
LEFT JOIN attendmeeting 
ON attendmeeting.username = members.username 
WHERE attendmeeting.username IS NULL 
ORDER BY members.username DESC

编辑：

SELECT members.username 
FROM members 
LEFT JOIN attendmeeting 
ON attendmeeting.username = members.username 
WHERE attendmeeting.username IS NULL
    AND attendmeeting.username = 2
ORDER BY members.username DESC

HTH

Answer 2

SELECT username FROM members WHERE username NOT IN(SELECT username FROM attendmeeting WHERE meetingid=?) ORDER BY username ASC

我正在寻找的查询。

不喜欢两张桌子

2 个答案: