CREATE TRIGGER ad_hub_updates_1
AFTER DELETE ON
    hub_updates
FOR EACH ROW
BEGIN

    SELECT debug(
        'TRIGGER ad_hub_updates_1',
        OLD.hub_id,
        OLD.default_location_id
    );

    INSERT OR IGNORE INTO
        hub_tomerge(hub_id) VALUES (OLD.hub_id);

    UPDATE
        hub_tomerge
    SET
        default_location_id = default_location_id +
        (OLD.default_location_id IS NOT NULL)
    WHERE
        hub_id = OLD.hub_id
    ;

END;