Database Queries

Now that we have Mongoose setup and a data model for our ideas, we can use really easy methods to query our database. We will be using the Idea model that we created in the last lesson.

Let's go into our routes/ideas.js

We will start by importing the Idea model:

const Idea = require('../models/Idea');

Async/await

Mongoose methods return promises, so we can use async/await to handle the promises. We will be using async/await in all of our routes. So before the callback function, we will add async and then we can use await before the Mongoose method.

Get All Ideas

Now in the GET / route, let's get the ideas from the database and send them instead of the hardcoded ones. Yes, I know there are not any in there yet, but that's ok, we will still just get an empty array.

We can do this easily by using the find() method.

// Get all posts
router.get('/', async (req, res) => {
  try {
    const ideas = await Idea.find();
    res.json({ success: true, data: ideas });
  } catch (err) {
    res.json({ success: false, message: err });
  }
});

Now, go to Postman and go to the route http://localhost:5000/api/ideas. You should see an empty array.

Create an Idea

Now let's add a new idea to the database.We can use the save() method to save the idea to the database.

// Create idea
router.post('/', async (req, res) => {
  const idea = new Idea({
    text: req.body.text,
    tag: req.body.tag,
    username: req.body.username,
  });

  try {
    const savedIdea = await idea.save();
    res.json({ success: true, data: savedIdea });
  } catch (err) {
    res.json({ success: false, message: err });
  }
});

Now, go to Postman and create a new POST request to http://localhost:5000/api/ideas. Be sure to add the text, tag and username in the body of the request. You should get a response with the idea that was created.

Now, make a get request to http://localhost:5000/api/ideas and you should see the idea that you just created.

It has the text, tag, username, date and an _id field. This is the unique identifier for the idea. We will use this to get a single idea and to delete an idea. You will also see __v, this is the version number of the document. This is used by Mongoose to keep track of changes to the document.

Single Idea

Let's update the route that gets a single idea by it's ID. We can use the findById() method to get a single idea by it's ID.

// Get single idea
router.get('/:id', async (req, res) => {
  try {
    const idea = await Idea.findById(req.params.id);
    res.json({ success: true, data: idea });
  } catch (err) {
    res.json({ success: false, message: err });
  }
});

Go to Postman and make a GET request to http://localhost:5000/api/ideas/ID_OF_IDEA. You should get the idea that you created.

Update Idea

Now for the update route, we will is findByIdAndUpdate() to update the text and tag

// Update idea
router.put('/:id', async (req, res) => {
  try {
    const updatedIdea = await Idea.findByIdAndUpdate(
      req.params.id,
      {
        $set: {
          text: req.body.text,
          tag: req.body.tag,
          username: req.body.username,
        },
      },
      { new: true }
    );
    res.json({ success: true, data: updatedIdea });
  } catch (err) {
    res.json({ success: false, message: err });
  }
});

Now, make a PUT request to http://localhost:5000/api/ideas/ID_OF_IDEA and update the title and body. You should get the updated idea back.

Delete Idea

Finally, we will add the code to delete the idea. We will use the findByIdAndDelete() method to delete the idea.

// Delete idea
router.delete('/:id', async (req, res) => {
  try {
    await Idea.findByIdAndDelete(req.params.id);
    res.json({ success: true, data: {} });
  } catch (err) {
    res.json({ success: false, message: err });
  }
});

We now have a fully functional API that can create, read, update and delete ideas from the database.

In the next section, we will create a simple front-end to interact with our API.