text: CREATE TABLE users_roles (
    user_id INT UNSIGNED NOT NULL,
    role_id INT UNSIGNED NOT NULL,
  
    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  
    UNIQUE (user_id, role_id),
  
    FOREIGN KEY (user_id) REFERENCES users(id),
    FOREIGN KEY (role_id) REFERENCES roles(id)
  
  )