WITH is_owner AS (SELECT ?::boolean AS p),
     player_id AS (SELECT ?::integer AS p),
     player_group_id AS (SELECT ?::integer AS p)
INSERT INTO players_groups (is_owner, player_id, player_group_id)
  SELECT is_owner.p, player_id.p, player_group_id.p
  FROM is_owner, player_id, player_group_id
  WHERE EXISTS (SELECT 1 FROM players_groups
                WHERE player_id = ? AND player_group_id = ?
                AND is_owner = TRUE)
  ON CONFLICT (player_id, player_group_id) DO UPDATE
  SET is_owner = (SELECT p FROM is_owner);