Postgres - aggregate two columns into one item

Question

I would like to aggregate two columns into one "array" when grouping.

Assume a table like so:

friends_map: ================================= user_id    friend_id    confirmed ================================= 1          2            true 1          3            false 2          1            true 2          3            true 1          4            false 

I would like to select from this table and group by user_id and get friend_id and confirmed as a concatenated value separated by a comma.

Currently I have this:

SELECT user_id, array_agg(friend_id) as friends, array_agg(confirmed) as confirmed FROM friend_map WHERE user_id = 1 GROUP BY user_id 

which gets me:

================================= user_id    friends      confirmed ================================= 1         [2,3,4]       [t, f, f] 

How can I get:

================================= user_id    friends      ================================= 1         [ [2,t], [3,f], [4,f] ] 

Answer 1

SELECT user_id, array_agg((friend_id, confirmed)) as friends FROM friend_map WHERE user_id = 1 GROUP BY user_id  user_id |           array_agg             --------+--------------------------------       1 | {"(2,true)","(3,false)","(4,false)"}