Mongoose Queries Model.updateOne() Function

The Queries Model.updateOne() function of the Mongoose API is used to update an existing document with the information mentioned in the “update” object. It updates only the first document that is returned in the filter.

Syntax:

Model.updateOne(filter, update, options, callback )

Parameters: It accepts the following 4 parameters as mentioned above and described below:

• filter: It is a mongoose object which identifies the existing document to update.
• update: It is a mongoose object which is the document that will update the data in the existing document.
• options: It is an optional mongoose object which is derived from Query.prototype.setOptions().
• callback: It is a callback function that accepts 2 parameters: error and writeOpResult.

Return type: It returns a Query object as a response.

Setting up Node.js Mongoose Module:

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

The below examples will demonstrate the updateOne() method.

Example 1: In this example, we will use this method to update an existing document that has the age “19”.

Javascript

const mongoose = require('mongoose')

// Database connection
mongoose.connect('mongodb://localhost:27017/query-helpers',
    {
        dbName: 'event_db',
        useNewUrlParser: true,
        useUnifiedTopology: true
    }, err => err ? console.log(err)
        : console.log('Connected to database'));

const personSchema = new mongoose.Schema({
    name: {
        type: String,
        select: false
    },
    age: {
        type: Number,
    }
});

const personsArray = [
    {
        name: 'Luffy',
        age: 19
    },
    {
        name: 'Nami',
        age: 30
    },
    {
        name: 'Zoro',
        age: 35
    }
]

const Person = mongoose.model('Person', personSchema);

(async () => {
    await Person.insertMany(personsArray);
    const res = await Person.updateOne({ age: 19 }, { age: 23 });
    console.log(res.modifiedCount);
})()

Step to Run Application: Run the application using the following command from the root directory of the project:

node main.js

Output:

GUI Representation of the Database using MongoDB Compass:

Example 2: In this example, we will use this method to update an existing document that has the name “Luffy”.

Javascript

const mongoose = require('mongoose')

// Database connection
mongoose.connect('mongodb://localhost:27017/query-helpers',
    {
        dbName: 'event_db',
        useNewUrlParser: true,
        useUnifiedTopology: true
    }, err => err ? console.log(err)
        : console.log('Connected to database'));

const personSchema = new mongoose.Schema({
    name: {
        type: String,
        select: false
    },
    age: {
        type: Number,
    }
});

const personsArray = [
    {
        name: 'Luffy',
        age: 19
    },
    {
        name: 'Nami',
        age: 30
    },
    {
        name: 'Zoro',
        age: 35
    }
]

const Person = mongoose.model('Person', personSchema);

(async () => {
    await Person.insertMany(personsArray);
    const res = await Person.updateOne(
        { name: 'Luffy' }, { name: 'Shanks' });
    console.log(res.modifiedCount);
})()

Step to Run Application: Run the application using the following command from the root directory of the project:

node main.js

Output:

GUI Representation of the  Database using MongoDB Compass:

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