ORM for JavaScript (Node.js): comparison of Sequelize, TypeORM, Prisma

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

When developing a server-side application in Node.js, the question of interacting with a database inevitably arises sooner or later. Writing raw SQL queries is a labor-intensive and error-prone task. ORM (Object-Relational Mapping) libraries come to the rescue, allowing you to work with database tables as if they were regular JavaScript objects. In this article, we will compare the three most popular ORMs for Node.js: Sequelize, TypeORM, and Prisma, and provide illustrative code examples.

1. Sequelize

Sequelize is one of the oldest and most mature ORMs for Node.js. It supports PostgreSQL, MySQL, MariaDB, SQLite, and Microsoft SQL Server. Sequelize uses a classic approach with models and promises (or async/await).

Installation

npm install sequelize pg pg-hstore

Example: model definition and query

const { Sequelize, DataTypes } = require('sequelize');const sequelize = new Sequelize('database', 'user', 'password', {  host: 'localhost',  dialect: 'postgres'});

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

async function createUser() {  await sequelize.sync();  const user = await User.create({ name: 'Ivan', email: 'ivan@example.com' });  console.log(user.toJSON());}createUser();

Sequelize Features

• Maturity and a large community.
• Support for transactions, migrations, and seed data.
• Flexible association system (hasOne, hasMany, belongsToMany).
• Drawback: sometimes verbose syntax and complex debugging.

2. TypeORM

TypeORM is an ORM that can work with both JavaScript and TypeScript. It supports the same DBMS as Sequelize and offers two approaches: Active Record and Data Mapper. TypeORM also actively uses decorators, making the code more declarative.

Installation

npm install typeorm reflect-metadata pg

Example: model with decorator and query

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

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

  @Column()  name: string;

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

async function createUser() {  const connection = await createConnection({    type: 'postgres',    host: 'localhost',    database: 'test',    entities: [User],    synchronize: true  });  const user = new User();  user.name = 'Maria';  user.email = 'maria@example.com';  await connection.manager.save(user);  console.log(user);}createUser();

TypeORM Features

• Excellent integration with TypeScript and decorators.
• Flexibility: choice between Active Record and Data Mapper.
• Support for migrations, event subscribers, and logging.
• Drawback: documentation is sometimes incomplete, frequent breaking changes.

3. Prisma

Prisma is a modern ORM that differs significantly from its predecessors. Instead of models in code, you describe the data schema in a special file schema.prisma, and Prisma generates a type-safe client. This provides autocompletion in the IDE and minimizes errors.

Installation

npm install @prisma/clientnpx prisma init

Example: schema and query

schema.prisma:

datasource db {  provider = "postgresql"  url      = env("DATABASE_URL")}

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

JavaScript code:

const { PrismaClie