sql - MySQL Contact multiple right joined rows into one column -

if have this

users

id user  1 john    2 tom 

and

states

user_id state  1        ma 1        ca 2        va 

how result set is:

id user states   1 john  ma,ca 2 tom   va 

i think has group contact, can't work.

as suggested, group_concat way go - need group by users' columns:

select   u.id, u.user, group_concat(s.state)     users u join     states s on u.id = s.user_id group u.id, u.user