Mongoose Create Document If Not Exists Otherwise Update Return Document In Either Case

When working with MongoDB and Mongoose in your Node.js applications, you may often come across a common scenario: you want to create a new document if it doesn't exist in the database, and if it does exist, update its values. Fortunately, Mongoose provides a simple and efficient way to achieve this using the `findOneAndUpdate` method.

To implement the "create if not exists, update if it exists" logic, you can follow these steps:

Firstly, ensure you have Mongoose installed in your project by running `npm install mongoose`.

Next, define your Mongoose schema and model as usual. For instance, let's say we have a simple schema for a user:

const mongoose = require('mongoose');

const userSchema = new mongoose.Schema({
  username: String,
  email: String,
  age: Number
});

const User = mongoose.model('User', userSchema);

Now, let's proceed with the logic to create a new document if the user doesn't exist, and update it if it does:

const query = { email: '[email protected]' }; // Define the query to find the user

const update = { 
  username: 'example',
  age: 25
}; // Set the values to update if the user exists

const options = { 
  new: true, 
  upsert: true 
}; // Using the upsert option ensures a new document is created if the user is not found

User.findOneAndUpdate(query, update, options, (error, user) => {
  if (error) {
    console.error(error);
    return;
  }

  console.log('User:', user);
});

In the above code snippet, we are using `findOneAndUpdate` to search for a user with the provided email. If a user with the specified email is found, the `update` object's values are applied. If not found, a new user document is created with the email, username, and age provided in the `update` object.

By setting the `new: true` option, the method returns the updated user document. The `upsert: true` option combines the functionalities of insert and update. If a user with the specified email is not found, a new user document is inserted.

Remember to handle any errors that may occur during the process to ensure a smooth user experience in your application.

In summary, using Mongoose's `findOneAndUpdate` method with the `upsert` option allows you to easily implement the logic of creating a document if it doesn't exist, updating it if it does, and returning the document in either case. This approach simplifies your code and enhances the efficiency of your database operations.

That's all for now! Happy coding!