@Entity({ name: 'person' })
export class PersonEntity extends BaseEntity {
  @PrimaryColumn()
  id!: number;

  @OneToMany(() => AnimalEntity, ({ person }: AnimalEntity) => person, {
    onDelete: 'CASCADE',
    cascade: true,
  })
  pets!: AnimalEntity[];
}


@Entity({ name: 'beings' })
@TableInheritance({ column: { type: 'varchar', name: 'type' } })
export class BeingEntity extends BaseEntity {
  @PrimaryColumn()
  id!: number;
}



@ChildEntity('animal')
export class AnimalEntity extends BaseEntity {
  @Column({ type: 'varchar' })
  name!: string;
}

@ChildEntity('cat')
export class CatEntity extends AnimalEntity {
  // Cat stuff
}

@ChildEntity('dog')
export class DogEntity extends AnimalEntity {
  // Dog stuff
}

const pets = [
  this.catRepo.create({
    name: 'felix',
    // Cat stuff
  }),
  this.dogRepo.create({
    name: 'spike',
    // Dog stuff
  }),
];
const person = this.personRepo.create({ pets });


await this.connection.manager.save(person);

// Created [
//     { type: 'cat', personId: 42, name: 'felix', other cat stuff }, 
//     { type: 'dog', personId: 42, name: 'spike', other dog stuff }, 
//     { id: 42, people stuff }
//  ]

// Created [
//     { type: 'animal', personId: 42, name: 'felix', other cat stuff }, 
//     { type: 'animal', personId: 42, name: 'spike', other dog stuff }, 
//     { id: 42, people stuff }
//  ]

const pets = [
  this.catRepo.create({
    name: 'felix',
    personId: 42, // assuming i know the personId in advance
    // Cat stuff
  }),
  this.dogRepo.create({
    name: 'spike',
    personId: 42, // assuming i know the personId in advance
    // Dog stuff
  }),
];
const person = this.personRepo.create({  id: 42 });


// What's important here is that the `cat` and `dogs` are saved individually.
// The drawback is that because we dont embed the pet entities, the linking must be done manually.
await this.connection.manager.save([...pets, person]);

// Created [
//     { type: 'cat', personId: 42, name: 'felix', other cat stuff }, 
//     { type: 'dog', personId: 42, name: 'spike', other dog stuff }, 
//     { id: 42, people stuff }
//  ]