I have tried the following, but IF FOUND is always false for some reason:
_versus := JSONB_BUILD_ARRAY(
SUM(CASE WHEN (player1 = in_uid AND state1 = 'won') OR (player2 = in_uid AND state2 = 'won') THEN 1 ELSE 0 END)::integer,
SUM(CASE WHEN (player1 = in_uid AND state1 = 'lost') OR (player2 = in_uid AND state2 = 'lost') THEN 1 ELSE 0 END)::integer,
SUM(CASE WHEN (player1 = in_uid AND state1 = 'draw') OR (player2 = in_uid AND state2 = 'draw') THEN 1 ELSE 0 END)::integer
)
FROM words_games
WHERE finished IS NOT NULL
AND (
(player1 = in_uid AND player2 = in_opponent) OR
(player2 = in_uid AND player1 = in_opponent)
);
IF FOUND THEN
out_data := JSONB_INSERT(out_data, '{versus}', _versus);
END IF;