MySQL group concat conversion to Postgres using two concatenated columns

Question

How can I create a similar query using Postgres to recreate this MySQL version.

SELECT u.id, GROUP_CONCAT(CONCAT(r.firstname,' ',r.lastname, ' [', r.type,']') SEPARATOR ', ') AS names
FROM reference r, users u
WHERE r.user_id = u.id
GROUP BY r.user_id

Answer 1

Use string_agg. Also, use explicit join syntax.

SELECT u.id, string_agg(r.firstname || ' ' || r.lastname || ' [' || r.type || ']' , ', ') AS names
FROM reference r join users u
on r.user_id = u.id
GROUP BY r.user_id