title: Add Full Populated Object to another Schema object
body: <p>I am trying to save my full (populated products) cart in my purchases. But I am still getting product Ids in my purchases but not whole populated product from that cart.</p>
  <p>This is the purchases -&gt; cart-&gt; product, should be populated full object but I am getting only Object Ids of products in the database.</p>
  <p><a href="https://i.stack.imgur.com/YIozs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YIozs.png" alt="enter image description here" /></a></p>
  <p>The Population query is like this.</p>
  <pre><code>Cart.findOne({ userId }).populate(&quot;products.id&quot;).exec()
  </code></pre>
  <p>And then I am saving full cart object like this in my purchases</p>
  <p><a href="https://i.stack.imgur.com/CtXsb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CtXsb.png" alt="enter image description here" /></a></p>
  <p>and its type is Object in my schema</p>
  <p><a href="https://i.stack.imgur.com/eo04l.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eo04l.png" alt="enter image description here" /></a></p>
  <p>Even I am getting full object in the response but it is not saving in the database.</p>
  <p><a href="https://i.stack.imgur.com/0KHFa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0KHFa.png" alt="enter image description here" /></a></p>
  <p>So why not in database?</p>