CREATE TRIGGER bu_hub_locations_tomerge_1
BEFORE UPDATE OF
    resolve
ON
    hub_locations_tomerge
FOR EACH ROW WHEN
    NEW.resolve = 1 AND
    OLD.location != 0
BEGIN

    SELECT debug(
        'TRIGGER bu_hub_locations_tomerge_1',
        OLD.hub_location_id
    );


    UPDATE
        hub_locations
    SET
        location = (
            SELECT
                hub_location_updates.location
            FROM
                hub_location_updates
            INNER JOIN
                updates
            ON
                updates.id = hub_location_updates.update_id
            WHERE
                hub_location_updates.hub_location_id =
                    OLD.hub_location_id AND
                hub_location_updates.location IS NOT NULL
            ORDER BY
                updates.mtime DESC,
                updates.uuid
            LIMIT
                1
        )
    WHERE
        id = OLD.hub_location_id
    ;

END;