ORM for Node.js: comparison and code examples

ORM for JavaScript (Node.js): comparison and examples

When developing server-side applications on Node.js, interacting with a database is one of the key tasks. Object-Relational Mapping (ORM) allows you to work with relational databases through JavaScript objects, eliminating the need to write raw SQL. In this article, we will review three popular ORMs: Sequelize, TypeORM, and Prisma, compare their features, and provide practical examples.

1. Sequelize

Sequelize is one of the oldest and most mature ORMs for Node.js. It supports PostgreSQL, MySQL, MariaDB, SQLite, and MSSQL. It works with promises and async/await.

Installation and setup

npm install sequelize sequelize-clinpm install pg pg-hstore # for PostgreSQL

Model and query example

const { Sequelize, DataTypes } = require('sequelize');const sequelize = new Sequelize('postgres://user:pass@localhost:5432/mydb');

// Defining a modelconst User = sequelize.define('User', {  name: { type: DataTypes.STRING, allowNull: false },  email: { type: DataTypes.STRING, unique: true }});

// Creating a recordconst user = await User.create({ name: 'Ivan', email: 'ivan@example.com' });

// Searching with a filterconst users = await User.findAll({ where: { name: 'Ivan' } });

// Updatingawait User.update({ email: 'new@example.com' }, { where: { id: 1 } });

Pros and cons

+ Large community, extensive documentation
+ Support for migrations and seeds
- Verbose syntax for complex queries
- No built-in TypeScript support

2. TypeORM

TypeORM is an ORM oriented towards TypeScript, but it also works with plain JavaScript. It supports decorators, Active Record, and Data Mapper. It works with most popular DBMS.

Installation and setup

npm install typeorm reflect-metadatanpm install pg # for PostgreSQL

Model example with decorators

import { Entity, PrimaryGeneratedColumn, Column, createConnection } from 'typeorm';

@Entity()export class User {  @PrimaryGeneratedColumn()  id: number;

  @Column()  name: string;

  @Column({ unique: true })  email: string;}

// Usageconst connection = await createConnection();const userRepo = connection.getRepository(User);const user = await userRepo.save({ name: 'Anna', email: 'anna@example.com' });const users = await userRepo.find({ where: { name: 'Anna' } });

Pros and cons

+ Excellent TypeScript support
+ Two approaches: Active Record and Data Mapper
- Complex configuration for beginners
- Slow migrations in large projects

3. Prisma

Prisma is a modern ORM that uses its own schema language and generates a type-safe client. It is considered the most performant and developer-friendly.

Installation and setup

npm install @prisma/clientnpx prisma init

Schema definition (schema.prisma)

model User {  id    Int     @id @default(autoincrement())  name  String  email String @unique}

Query example

import { PrismaClient } from '@prisma/client';const prisma = new PrismaClient();

// Creatingconst user = await prisma.user.create({  data: { name: 'Olga', email: 'olga@example.com' }});

// Searchingconst users = await prisma.user.findMany({ where: { name: 'Olga' } });

// Updatingawait prisma.user.update({  where: { id: 1 },  data: { email: 'new@example.com' }});