title: Retrieving data from Post Schema without return it in Mongoose
body: <p>so what I'm trying to do is in my PostSchema there's a userId field that store the id of the post owner, any idea how can I get the post owner information from the id? What I've tried so far</p>
  <p>Create Post</p>
  <pre><code>createPost: async (req, res) =&gt; {
      const users = await User.findById(req.body.userId);
      const makePost = {
        ...req.body,
        username: users.username,
        avaUrl: users.profilePicture,
        theme: users.theme,
      };
      const newPost = new Post(makePost);
      try {
        const savedPost = await newPost.save();
        res.status(200).json(savedPost);
      } catch (err) {
        res.status(500).json(err);
      }
    },
  </code></pre>
  <p>So I was using this returned information to display the user avatar on the frontend, but the problem is now if I tried to update the user information, the post avaUrl won't change</p>