What is the difference between TypeORM's Active Record and Data Mapper patterns?

Difference between TypeORM's Active Record and Data Mapper patterns:

Active Record Pattern:

• Entity classes directly contain data access logic
• Use extends BaseEntity or @Entity() decorator
• Example:

  typescript
  @Entity()
  export class User extends BaseEntity {
    @PrimaryGeneratedColumn()
    id: number;
    
    static async findByName(name: string) {
      return this.createQueryBuilder('user')
        .where('user.name = :name', { name })
        .getMany();
    }
  }
  
  // Usage
  const user = new User();
  user.name = 'John';
  await user.save();

Data Mapper Pattern:

• Entity classes only contain data, no data access logic
• Use Repository for data operations
• Example:

  typescript
  @Entity()
  export class User {
    @PrimaryGeneratedColumn()
    id: number;
  }
  
  // Usage
  const userRepository = dataSource.getRepository(User);
  const user = new User();
  user.name = 'John';
  await userRepository.save(user);

Recommendations:

• Active Record: Suitable for small projects, rapid development
• Data Mapper: Suitable for large projects, better separation of concerns and testability