Mongoose Document Model() API

The Mongoose Document APIModel() method of the Mongoose API is used on the Document model. It allows to create a MongoDB class. Using this method we can create model that can interact with MongoDB for all operations. Let us understand the APIModel() method using an example.

Syntax:

mongoose.model( doc, fields, skipId );

Parameters: This method accepts three parameters as discussed below:

• doc: It is used to specify the document object.
• fields: It is used to specify various objects in the form of JavaScript objects.
• skipid: It is used to specify _id should be there in documents.

Return Value: This method returns the subclass of the Document class.

Setting up Node.js application:

Step 1: Create a Node.js application using the following command:

npm init

Step 2: After creating the NodeJS application, Install the required module using the following command:

npm install mongoose

Project Structure: The project structure will look like this: 

Database Structure: The database structure will look like this, the following documents are present in the collection.

Example 1: In this example, we are illustrating the functionality of Mode() class. We are creating new document object of Customer model using subclass of Document class i.e Customer.

Filename: app.js

Javascript

// Require mongoose module
const mongoose = require("mongoose");

// Set Up the Database connection
const URI = "mongodb://localhost:27017/geeksforgeeks";

const connectionObject = mongoose.createConnection(URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
});

const Customer = connectionObject.model(
    "Customer",
    new mongoose.Schema({
        name: String,
        address: String,
        orderNumber: Number,
    })
);

const document = new Customer({
    name: "Harshit",
    address: "Pune",
    orderNumber: 45
});
document.save().then(res => {
    console.log(res);
})

Step to run the program: To run the application execute the below command from the root directory of the project:

node app.js

Output:

{
  name: 'Harshit',
  address: 'Pune',
  orderNumber: 45,
  _id: new ObjectId("63c1c0294a390b560860be13"),
  __v: 0
}

Example 2: In this example, we are illustrating the functionality of Model() class.  At the end, we are sending an object to Customer model constructor.

Filename: app.js

Javascript

// Require mongoose module
const mongoose = require("mongoose");

// Set Up the Database connection
const URI = "mongodb://localhost:27017/geeksforgeeks";

const connectionObject = mongoose.createConnection(URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
});

const Customer = connectionObject.model(
    "Customer",
    new mongoose.Schema({
        name: String,
        address: String,
        orderNumber: Number,
    })
);

const newDocument = {
    name: "Kalpesh",
    address: "Mumbai",
    orderNumber: 85
}

new Customer(newDocument).save().then(res => {
    console.log(res);
})

Step to run the program: To run the application execute the below command from the root directory of the project:

node app.js

Output: 

{
  name: 'Kalpesh',
  address: 'Mumbai',
  orderNumber: 85,
  _id: new ObjectId("63c1c13545be37f87a052528"),
  __v: 0
}

Reference: https://mongoosejs.com/docs/api/model.html#model_Model