CREATE TRIGGER ad_hub_location_updates_1
AFTER DELETE ON
    hub_location_updates
FOR EACH ROW
BEGIN

    SELECT debug(
        'TRIGGER ad_hub_location_updates_1',
        OLD.update_id,
        OLD.hub_location_id,
        OLD.location
    );

    INSERT OR IGNORE INTO
        hub_locations_tomerge(hub_location_id)
    VALUES
        (OLD.hub_location_id)
    ;

    UPDATE
        hub_locations_tomerge
    SET
        location = location + (OLD.location IS NOT NULL)
    WHERE
        hub_location_id = OLD.hub_location_id
    ;

END;