Mongoose schema for article

Modeling a separate schema for comment is not a good idea in my humble opinion, since it is a classic case of one to few mapping which is an ideal use case for embedding the document. To give you a basic idea about data modeling i am quoting here

You need to consider two factors:

• Will the entities on the “N” side of the One-to-N ever need to stand alone?
• What is the cardinality of the relationship: is it one-to-few; one-to-many; or one-to-squillions?

Based on these factors, you can pick one of the three basic One-to-N schema designs:

• Embed the N side if the cardinality is one-to-few and there is no need to access the embedded object outside the context of the parent object
• Use an array of references to the N-side objects if the cardinality is one-to-many or if the N-side objects should stand alone for any reasons
• Use a reference to the One-side in the N-side objects if the cardinality is one-to-squillions

Please refer to a very well written and articulated post 6 Rules of Thumb for MongoDB Schema Design: Part 1 from mongodb blogs.

Even after this if you think it is a good idea to link to another schema please refer to this SO question - Referencing another schema in Mongoose

so I found a solution for this:

// :id is all articles with all idsrouter.post('/:id', function (req, res) {  let comment = {};  comment.body = req.body.body;  comment.user = req.user;  comment.date = new Date(Date.now()).toDateString();  // Express validator  req.checkBody('body').len(5, 100);  let errors = [];  errors = req.validationErrors();  if(errors) {    Article.findById(req.params.id, function (err, article) {      if(err)throw err;      req.flash('danger', 'Body minimum length is 5 and maximum 100!');      res.redirect('/articles/'+article.id);    });  } else {    Article.findById(req.params.id, function (err, article) {      if(err)throw err;     article.comments.push({'body':comment.body,'user':comment.user,'date':comment.date});      article.save(function (err) {        if (err) {          throw err;        }else {          req.flash('success', 'Comment added!');          res.redirect('/articles/'+article.id);        }      });    });  }});

EDIT: code above in more readable form:

router.post('/:id', async (req, res) => {  let article = await Article.findById(req.params.id);  if (!article) res.status("403");  let articleUrl = "/articles/${article.id}";  let comment = {    body: req.body.body,    user: req.user,    date: new Date(Date.now()).toDateString();  };  if (commment.body.lengh >= 100 || comment.body.length <= 5) {    req.flash('danger', 'Body minimum length is 5 and maximum 100!');    return res.redirect(articleUrl);  }  articles.comments.push(comment);  await article.save();  req.flash('success', 'Comment added!');  res.redirect(articleUrl);});