Question

I have two MySQL tables: MEMBERS and POSTS. I need to make a query that will have following meaning:

Select all USERs that have some (>0) records in POSTS table =>
From them Select a USER who has the biggest ADS value in MEMBERS table.

I tried following thing:

"SELECT * FROM posts WHERE user=(select user from members where ads=(select Max(ads) from members))'

But this has a bug, that when USER with Max value in MEMBERS, has no records in POSTS table – SQL returns empty result.

My guess is that I should tell MySQL to choose Max value not from all rows, but only from pre-defined, but I don’t know how to do it and if it’s possible.

Can someone help me?

Answer 1

SELECT m.*
FROM members AS m
WHERE EXISTS
      ( SELECT *
        FROM posts AS p 
        WHERE p.member_id = m.member_id
      )
ORDER BY ads DESC
LIMIT 1