join - MySQL - Select in same table -

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i need use mysql show users (a) not follow b, (a) followed b. gonna used suggest connections on social media website.

my table structure:

id followed follower

i've tried use left join or not exists, didn't work.

@drapp shows me how user left join on query. works. now, how add users information on query (left join + inner join).

inner join need follow table , user table (inner join users on follow.follower = user.id)

users`s table structure:

id name

given scenario of sample data of "yourtable"

id  follower  followed 1           c 2   b         c 3   b         d 4   b         e 5   c         b 6   d

the people followed "b" include "c", "d" , "e" users. that, user "c" follows "b". so, looking no match a/b, b/a type of combination. basis of left-join. clause querying records based on user "b" considering originating "follower".

select       yt.followed,       u.name          yourtable yt          left join yourtable yt2             on yt.followed = yt2.follower             , yt.follower = yt2.followed          join users u             on yt.followed = u.id              yt.follower = 'b'       , yt2.followed null

to name, notice join original table based on user "b", not finding corrresponding inverse match. so, joining on original record's followed (who "b" following) user table same id in user table. grab user's name query.


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