NestJS – ORM (TypeORM)

NestJS

ORM (TypeORM)

Defining entities and using repositories with TypeORM in NestJS.

Define Entity: Create a class decorated with `@Entity()` to represent a database table.

📄src/users/user.entity.ts
typescript

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

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

  @Column({ length: 50 })
  username: string;

  @Column()
  email: string;

  @Column({ default: true })
  isActive: boolean;

  @CreateDateColumn()
  createdAt: Date;
}

Repository Injection: Inject the repository into a service to perform database operations.

📄src/users/users.service.ts
typescript

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User } from './user.entity';

@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User)
    private usersRepository: Repository<User>,
  ) {}

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

  findOne(id: number): Promise<User | null> {
    return this.usersRepository.findOneBy({ id });
  }

  async remove(id: number): Promise<void> {
    await this.usersRepository.delete(id);
  }
}