group_concat mysql子查询仅返回一项

Question

I have two tables, scoreTable and users. I am trying to group by hash on scoreTable but selecting all the user names that have that hash. scoreTable only has the ids

SELECT st.score,
GROUP_CONCAT(st.uid) as userList
FROM scoreTable st
GROUP BY hash

For the above query I get the list of user Ids in userList: '1,2,3,4'

What I would love to get is the actual "names" instead of the ids - the names are on another table (users)

SELECT st.score,
(SELECT group_concat(d.name) from users d d where d.uid = st.uid))
FROM scoreTable st
GROUP BY hash

But for some reason this only displays ONE user (the user with the first id).

Answer 1

Just join on the users table:

SELECT   st.score, group_concat(d.name)
FROM     scoreTable st
JOIN     users d ON d.uid = st.uid
GROUP BY hash