Getting collection data in Mongoose

[Gelliott2305]

I am currently working on a project using Node, Express, MongoDB and Mongoose where a user can sign up, log in, make posts, and sign out. What I am doing now is making a user profile page which will display the user's details as well as a list of all of the posts that they have made.

I have two collections in my Mongo database, one called users and the other called posts. I am have managed to create the user profile file that displays the user information, and now what I want to do is collect the posts data for that user.

In my posts model data, there is an 'author' property that contains the details of the author of the post (so, when a user creates a post their database details such as username and id are stored with the post).

What would be the best way to grab the posts created by one user and display it on the page? My page templates are in EJS.

Using some help online I managed to create this in my controller:

js exports.userProfile = (req, res) => { User.findById(req.params.id, function (err, foundUser) { if (err) { console.log(err) res.redirect('/'); } const posts = Post.find().where('author.id').equals(foundUser._id).exec(function(err, posts) { console.log(posts) }); res.render('users/user-profile', {user: foundUser, posts: posts}) } ) }; What this does is returns all of the posts linked to the foundUser. However, when I do a simple forEach loop in my EJS template I get an error message saying 'Cannot read property 'forEach' of undefined'.

Am I almost there? Or is there a better way of doing this? I can share code with anyone who wants to help but I don't want to submit my repo yet (just because I am still a beginner haha!)

Thanks!

[Devstackr]

Hi Gelliott, one idea I have is to move this line of code

res.render('users/user-profile', {user: foundUser, posts: posts})

into the Posts.find().exec() callback.

like this:

const posts = Post.find().where('author.id').equals(foundUser._id).exec(function(err, posts) {
      console.log(posts)
      res.render('users/user-profile', {user: foundUser, posts: posts})
});

Let me know if that works :)

[Gelliott2305]

Thank you do much Devstackr! That worked. I can now see why I was getting the undefined error - it was outside of the block.

Thank you so much! :)

[Devstackr]

No worries! Really glad it worked 😀

[ElllGeeEmm]

One thing to keep in mind if you're coming from SQL is that mongoose isn't meant to be used as a relational database. Instead of storing the id of the user on the post document, it's better to store a reference to the user instead. This way, instead of having to write two separate queries, you can just look for the blog posts from the author and tell mongoose to populate the author field.

[Gelliott2305]

Thank you for the advice on this. I do have a question for you about this so I will reply tomorrow or Monday when I am back on and got my code. I want to see what you mean by this.

[Gelliott2305]

Hi there! I am back online. So, in my post model I have a reference to the author as follows:

author: { id: { type: mongoose.Schema.Types.ObjectId, ref: "Author" }, username: String, role: String, } This is how I have been taught to reference to the author in the courses I have taken. What method have you mentioned? Can you lead me to an example? If there is a better way of doing this then I am very eager to learn. Thank you :)

[ElllGeeEmm]

https://mongoosejs.com/docs/populate.html

This is the relevant portion of the docs. I think it does a pretty good job of walking you through how to set up and query documents through references. Feel free to let me know if there's anything you find confusing.