How to push data to another schema in nodejs mongodb

Question

thanks for click my question..

I have two schemas in mongodb, citySchema and destinationSchema. I want to make one to many relation. Each destination has one city and the city has many destinations.

This is my destinationSchema

var mongoose = require("mongoose");
var destinationSchema = new mongoose.Schema({
  name: String,
  image: String,
  description: String,
  city: {
    type: mongoose.Schema.Types.ObjectId,
    ref: "City"
  }
});

module.exports = mongoose.model("Destination", destinationSchema);

This is citySchema

var mongoose = require("mongoose");
var citySchema = new mongoose.Schema({
  name: String,
  image: String,
  description: String,
  destinations: [
    {
      type: mongoose.Schema.Types.ObjectId,
      ref: "Destination"
    }
  ]
});

module.exports = mongoose.model("City", citySchema);

And this is the post route to create new destination

router.post("/", function(req, res) {
  var name = req.body.name;
  var image = req.body.image;
  var description = req.body.description;
  var city = req.body.city;
  var newDestination = {
    name: name,
    image: image,
    description: description,
    city: city
  };
  Destination.create(newDestination, function(err, newCreatedDestination) {
    if (err) {
      console.log(err);
    } else {
      res.redirect("/admin/destinations");
    }
  });
});

This is my form to create a new destination

<select name="city">
   <% cities.forEach(function(city) { %>
      <option value=<%=city._id%> > <%= city.name %> </option>
   <% }) %>
 </select>

It works fine. But I want when i create a new destination, it push current destination id to city schema (destinations array) .

Sorry for my bad English. I appreciate every your answers and suggestions. And Thank you 😊

Answer 1

After you create a new destination, you can push that destination's id to the city destinations.

You can use the following route:

router.post("/", async (req, res) => {
  try {
    const { name, image, description, city } = req.body;

    let newDestination = { name, image, description, city };

    newDestination = await Destination.create(newDestination);

    let result = await City.findByIdAndUpdate(
      city,
      {
        $push: { destinations: newDestination._id }
      },
      { new: true }
    );

    res.redirect("/admin/destinations");
  } catch (err) {
    console.log(err);
    res.status(500).send("Something went wrong");
  }
});

Let's have an existing city like this:

{
    "destinations": [],
    "_id": "5e071f212e9ecd31508785c6",
    "name": "Padang",
    "image": "image 1",
    "description": "beautiful city",
    "__v": 0
}

If we want to add this city a destination, we can send this request body to our post route. Please note that as city value, we need to use an existing city id ( 5e071f212e9ecd31508785c6 ) like the one we have already.

{
    "name": "destination name",
    "image": "destination image",
    "description": "destination description",
    "city": "5e071f212e9ecd31508785c6"
}

The result will be like this:

A new destionation is created:

{
    "_id" : ObjectId("5e071fd51cd3600bb083b5e7"),
    "name" : "destination name",
    "image" : "destination image",
    "description" : "destination description",
    "city" : ObjectId("5e071f212e9ecd31508785c6"),
    "__v" : NumberInt(0)
}

And added to the city:

{
    "_id" : ObjectId("5e071f212e9ecd31508785c6"),
    "destinations" : [
        ObjectId("5e071fd51cd3600bb083b5e7")
    ],
    "name" : "Padang",
    "image" : "image 1",
    "description" : "beautiful city",
    "__v" : NumberInt(0)
}

Answer 2

After creating a destination, use mongoose findOneAndUpdate method to update the relevant city.

As the name implies, findOneAndUpdate() finds the first document that matches a given filter, applies an update, and returns the document.

Mongoose findOneAndUpdate