ALTER TABLE travel_1_trip_private_notes
    ADD COLUMN trip_day_id BIGINT UNSIGNED NULL AFTER trip_id,
    ADD COLUMN trip_day_item_id BIGINT UNSIGNED NULL AFTER trip_day_id;

ALTER TABLE travel_1_trip_private_notes
    ADD KEY idx_trip_private_notes_day (trip_day_id),
    ADD KEY idx_trip_private_notes_item (trip_day_item_id),
    ADD CONSTRAINT fk_trip_private_notes_day FOREIGN KEY (trip_day_id)
        REFERENCES travel_1_trip_days(id) ON DELETE CASCADE,
    ADD CONSTRAINT fk_trip_private_notes_item FOREIGN KEY (trip_day_item_id)
        REFERENCES travel_1_trip_day_items(id) ON DELETE CASCADE;
