CREATE TABLE IF NOT EXISTS reviews (
    id CHAR(36) PRIMARY KEY,
    product_id CHAR(36) NOT NULL,
    customer_id CHAR(36) NOT NULL,
    order_id CHAR(36) NOT NULL,
    rating TINYINT NOT NULL,
    comment TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    UNIQUE KEY unique_review (product_id, customer_id),
    FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE,
    FOREIGN KEY (customer_id) REFERENCES customers(id) ON DELETE CASCADE,
    FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE CASCADE,
    INDEX idx_product_id (product_id),
    INDEX idx_customer_id (customer_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;