array_to_string(ARRAY_AGG (text),',')
-----------------------------------------------------
SELECT
relative_label_content
FROM
frk_s.label_cor_gene
relative_label_content
------
AA
BB
CC
------------------------------------------------------
SELECT
frwybs,
array_to_string(
ARRAY_AGG (DISTINCT relative_label_content),
','
) as labels_content
FROM
frk_s.label_cor_gene
GROUP BY
frwybs
labels_content
------------
AA,BB,CC