CREATE TABLE users (
  id INT PRIMARY KEY NOT NULL,
  name VARCHAR(100) NOT NULL,
  age INT,
  email VARCHAR(100),
  country VARCHAR(2),
  is_active BOOLEAN DEFAULT true,
  created_at TIMESTAMPTZ NOT NULL
);

CREATE TABLE products (
  id INT PRIMARY KEY NOT NULL,
  name VARCHAR(100) NOT NULL,
  category VARCHAR(50),
  price DECIMAL(10,2) NOT NULL,
  in_stock BOOLEAN
);

CREATE TABLE orders (
  id INT PRIMARY KEY NOT NULL,
  user_id INT,
  order_date TIMESTAMPTZ NOT NULL,
  status VARCHAR(20) 
);

CREATE TABLE order_items (
  order_id INT NOT NULL,
  product_id INT NOT NULL,
  quantity INT NOT NULL,
  price_at_purchase DECIMAL(10,2) NOT NULL,
  PRIMARY_KEY (order_id, product_id)
);