postgresql concatenate multiple rows in group by

The solution for this is noted below

postgresql concatenate multiple rows in group by

Solution

SELECT col_a,
array_to_string(array_agg(distinct col_b),',') AS Actor
FROM Table1
GROUP BY col_a;

-- Result:
-- MOVIE	ACTOR
-- A		1,2,3
-- B		4

Try other methods by searching on the site. That is if this doesn’t work