Mongoose, a powerful ODM (Object Data Modeling) library for MongoDB, seamlessly integrates with NestJS to handle database interactions efficiently. Integrating Mongoose with NestJS allows for easy management of MongoDB databases and models within a NestJS application. Let’s explore the steps to connect Mongoose with NestJS.

Prerequisites

Ensure you have Node.js and npm (Node Package Manager) installed on your machine, along with a MongoDB instance accessible to your NestJS application.

Setting Up a NestJS Project

1. Create a New NestJS Project

Generate a new NestJS project using the Nest CLI:

nest new my-nest-app

2. Install Required Dependencies

Navigate to your project directory and install the @nestjs/mongoose package:

npm install --save @nestjs/mongoose mongoose

This package facilitates seamless integration between NestJS and Mongoose.

Connecting Mongoose to NestJS

1. Configure Database Connection

Open the app.module.ts file and configure the MongooseModule with your MongoDB connection settings:

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';

@Module({
  imports: [
    MongooseModule.forRoot('mongodb://localhost:27017/mydatabase'),
    // Replace 'mydatabase' with your MongoDB database name
  ],
})
export class AppModule {}

Adjust the connection URL ('mongodb://localhost:27017/mydatabase') to match your MongoDB instance’s URL and database name.

2. Create Mongoose Models

Define Mongoose models representing your MongoDB collections. For example, create a User model:

import { Schema, Prop, SchemaFactory } from '@nestjs/mongoose';
import { Document } from 'mongoose';

@Schema()
export class User extends Document {
  @Prop()
  name: string;

  @Prop()
  email: string;

  // Add more properties as needed
}

export const UserSchema = SchemaFactory.createForClass(User);

3. Use Mongoose Models in NestJS Services

Inject the Mongoose models into NestJS services to perform CRUD operations:

import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';
import { User, UserDocument } from './user.schema';

@Injectable()
export class UserService {
  constructor(@InjectModel(User.name) private readonly userModel: Model<UserDocument>) {}

  async findAll(): Promise<User[]> {
    return this.userModel.find().exec();
  }

  // Implement other CRUD operations as needed
}

Conclusion

Connecting Mongoose with NestJS streamlines database interactions and allows for efficient handling of MongoDB data within a NestJS application. This integration facilitates seamless data modeling, CRUD operations, and database management, empowering developers to build robust and scalable applications with ease.