Building REST APIs with TypeORM and SQLite

TypeORM is a powerful Object-Relational Mapper (ORM) for TypeScript and JavaScript. Combined with SQLite, it provides an excellent foundation for building lightweight but powerful REST APIs.

Why TypeORM?

TypeORM offers several advantages:

• Decorator-based entity definitions that integrate seamlessly with TypeScript
• Multiple database support including SQLite, PostgreSQL, MySQL, and more
• Active Record and Data Mapper patterns
• Automatic migrations and schema synchronization

Setting Up TypeORM with SQLite

First, install the required packages:

bash
npm install typeorm better-sqlite3 reflect-metadata
npm install -D @types/better-sqlite3

Defining Entities

Entities in TypeORM are classes that map to database tables:

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

  @Column()
  name: string;

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

Creating a Data Source

The DataSource is the main entry point for TypeORM operations:

typescript
const dataSource = new DataSource({
  type: 'better-sqlite3',
  database: './data.db',
  entities: [User],
  synchronize: true,
});

CRUD Operations

With TypeORM, performing CRUD operations is straightforward:

typescript
// Create
const user = userRepo.create({ name: 'John', email: 'john@example.com' });
await userRepo.save(user);

// Read
const users = await userRepo.find();

// Update
user.name = 'Jane';
await userRepo.save(user);

// Delete
await userRepo.remove(user);

Conclusion

TypeORM with SQLite provides a powerful yet simple solution for data persistence in Node.js applications. Its TypeScript integration and decorator-based API make it a natural fit for modern TypeScript projects.