CREATE TABLE IF NOT EXISTS sales (
    id INT AUTO_INCREMENT PRIMARY KEY,
    transaction_id VARCHAR(255) NOT NULL UNIQUE,
    total_amount DECIMAL(10, 2) NOT NULL,
    payment_method VARCHAR(50) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE IF NOT EXISTS sale_items (
    id INT AUTO_INCREMENT PRIMARY KEY,
    sale_id INT NOT NULL,
    product_id INT NOT NULL,
    quantity INT NOT NULL,
    price DECIMAL(10, 2) NOT NULL,
    FOREIGN KEY (sale_id) REFERENCES sales(id) ON DELETE CASCADE,
    FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE SET NULL
);