-- Migration 006: Create order_items table
-- price is captured at time of purchase (does not follow later product price changes).

CREATE TABLE IF NOT EXISTS order_items (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  order_id INT UNSIGNED NOT NULL,
  product_id INT UNSIGNED DEFAULT NULL,
  product_title VARCHAR(200) NOT NULL,
  quantity INT NOT NULL DEFAULT 1,
  price DECIMAL(10,2) NOT NULL DEFAULT 0.00,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  KEY idx_order_items_order_id (order_id),
  KEY idx_order_items_product_id (product_id),
  CONSTRAINT fk_order_items_order FOREIGN KEY (order_id) REFERENCES orders (id) ON DELETE CASCADE,
  CONSTRAINT fk_order_items_product FOREIGN KEY (product_id) REFERENCES products (id) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;