CREATE TABLE IF NOT EXISTS ratings (
    id SERIAL PRIMARY KEY,
    order_id INT NOT NULL UNIQUE,
    restaurant_id INT NOT NULL,
    user_id INT NOT NULL,
    rating INT NOT NULL CHECK (rating >= 1 AND rating <= 5),
    review TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE CASCADE,
    FOREIGN KEY (restaurant_id) REFERENCES restaurants(id) ON DELETE CASCADE,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
);