title: How do I ensure that a referencing table also has data
body: <p>My Postgres database has the following schema where the the user can store multi profile images.</p>
  <pre><code>CREATE TABLE users(
      id INT GENERATE AS ALWAYS PRIMARY KEY,
      name VARCHAR(50)
  );
  
  CREATE TABLE images(
      id INT GENERATE AS ALWAYS PRIMARY KEY,
      url VARCHAR(50)
  );
  
  CREATE TABLE user_images(
      user_id INT REFERENCES users(id),
      image_id INT REFERENCES images(id)
  );
  </code></pre>
  <p>How do I ensure that when I insert a user object, I also insert at least one user image?</p>