ALTER TABLE fuel_price_history
    ADD COLUMN state_id BIGINT UNSIGNED NULL AFTER fuel_type_id,
    ADD KEY idx_fuel_price_history_state (state_id),
    ADD CONSTRAINT fk_fuel_price_history_state
        FOREIGN KEY (state_id) REFERENCES nigeria_states(id)
        ON UPDATE CASCADE
        ON DELETE SET NULL;

ALTER TABLE vehicle_fuel_entries
    ADD COLUMN state_id BIGINT UNSIGNED NULL AFTER fuel_type_id,
    ADD KEY idx_vehicle_fuel_entries_state (state_id),
    ADD CONSTRAINT fk_vehicle_fuel_entries_state
        FOREIGN KEY (state_id) REFERENCES nigeria_states(id)
        ON UPDATE CASCADE
        ON DELETE SET NULL;
