mysql-加入更多2个表

我正在尝试加入3个mysql表；朋友,用户和评论.

users:
id  | firstName | lastName
--------------------------
12  | edwin     | leon
9   | oscar     | smith
1   | kasandra  | rios

friends:
userId   | friendID
----------------------
   12    | 9
   9     | 12
   12    | 1
   1     | 12

comments:
commenter | comment  | commentDate
----------------------------
 12       |  hey     | Oct-2
 1        | Hmmmmmm  | Nov-1
 9        | ok       | Nov-2
 9        | testing  | Nov-2
 1        | hello    | Dec-20    
 1        | help     | Dec-20

因此,我想做的是选择所有用户朋友的评论.我想输出的是您朋友的评论：
例如：

for edwin leon (id 12) it would output this
friendID    | comment  | commentDate | firstName | lastName
-----------------------------------------------------------
   1        | Help     |    Dec-20   | kasandra  | rios
   1        | Hello    |    Dec-20   | kasandra  | rios
   9        | testing  |    Nov-2    | oscar     | smith
   9        | ok       |    Nov-2    | oscar     | smith
   1        | Hmmmm    |    Nov-1    | kasandra  | rios

它会得到所有朋友的评论,但不会得到他的评论.这是我的代码：

SELECT friends.friendID, users.firstName, users.lastName, comments.comment, comments.commentDate  
FROM users
  JOIN friends ON friends.userID = users.id
  JOIN comments ON comments.commenter = friends.friendID 
 WHERE users.id = '12' AND comments.commenter != '12'

它确实有效,但是我没有得到评论者的名字,而是得到了所有人edwin leon

解决方法:

您想要将用户表联接到friendId,而不是userid：

SELECT friends.friendID, users.firstName, users.lastName, comments.comment, comments.commentDate  
FROM users
  JOIN friends ON friends.friendID = users.id
  JOIN comments ON comments.commenter = friends.friendID 
 WHERE friends.userID = '12' AND comments.commenter != '12'

看到它在线运行：sqlfiddle