typeorm

---

1. Create a New Entity

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

  @Column()
  name: string;

  @Column()
  email: string;
}

2. Find All Users

const users = await userRepository.find();

3. Find a User by ID

const user = await userRepository.findOne(1);

4. Find Users by Name

const users = await userRepository.findByName("John");

5. Save a New User

const user = new User();
user.name = "John";
user.email = "[e-mail]";
await userRepository.save(user);

6. Update a User

const user = await userRepository.findOne(1);
user.name = "Jane";
await userRepository.save(user);

7. Delete a User

await userRepository.delete(1);

8. Create a Many-to-One Relationship

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

  @Column()
  userId: number;

  @ManyToOne(() => User, user => user.orders)
  user: User;
}

9. Create a One-to-Many Relationship

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

  @Column()
  name: string;

  @OneToMany(() => Order, order => order.user)
  orders: Order[];
}

10. Create a Many-to-Many Relationship

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

  @Column()
  name: string;

  @ManyToMany(() => Group, group => group.users)
  groups: Group[];
}

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

  @Column()
  name: string;

  @ManyToMany(() => User, user => user.groups)
  users: User[];
}

11. Use a Query Builder

const users = await userRepository.createQueryBuilder("user")
  .where("user.name like :name", { name: "%John%" })
  .getMany();

12. Use a Repository

const users = await userRepository.find({
  where: { name: "John" },
  order: { id: "ASC" },
  take: 10,
  skip: 0,
});

13. Use a Data Transformer

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

  @Column()
  name: string;

  @Transformer((value) => value.toUpperCase(), (value) => value.toLowerCase())
  email: string;
}

14. Use a Custom Repository

export class UserRepository extends Repository<User> {
  async findByName(name: string): Promise<User[]> {
    return this.find({ where: { name } });
  }
}

15. Use a Middleware

export function myMiddleware(req: Request, res: Response, next: NextFunction) {
  // Do something before the request is processed
  next();
  // Do something after the request is processed
}

16. Use a Plugin

export function myPlugin(connection: Connection) {
  // Do something when the connection is established
}

17. Use a Custom TypeORM Driver

export class MyDriver implements Driver {
  // Implement the Driver interface
}

18. Use a Custom TypeORM Query Runner

export class MyQueryRunner implements QueryRunner {
  // Implement the QueryRunner interface
}

19. Use a Custom TypeORM Entity Manager

export class MyEntityManager implements EntityManager {
  // Implement the EntityManager interface
}

20. Use a Custom TypeORM Schema Manager

export class MySchemaManager implements SchemaManager {
  // Implement the SchemaManager interface
}

21. Use a Custom TypeORM Migration

export class MyMigration implements Migration {
  // Implement the Migration interface
}

22. Use a Custom TypeORM Extension

export class MyExtension implements Extension {
  // Implement the Extension interface
}

23. Use a Custom TypeORM Interceptor

export class MyInterceptor implements Interceptor {
  // Implement the Interceptor interface
}

24. Use a Custom TypeORM Subscriber

export class MySubscriber implements Subscriber {
  // Implement the Subscriber interface
}

25. Use a Custom TypeORM Event Listener

export class MyEventListener implements EventListener {
  // Implement the EventListener interface
}