Initialize another entity during entity initialization (TypeORM)

Question

I have an entity Store that stores in itself

@Entity('shops')
export class ShopEntity{
  @PrimaryGeneratedColumn()
  id: number;

  @OneToOne(() => ScheduleEntity)
  @JoinColumn()
  schedule: ScheduleEntity;
}

I also have a Schedule entity

@Entity('schedules')
    export class ScheduleEntity {
      @PrimaryGeneratedColumn()
      id: number;
    
      @Column('jsonb')
      monday: DayDto;
    }

In the shop entity, I insert such an ordinary thing

  @AfterInsert()
  async createDefaultSchedule() {
    const schedule = new ScheduleEntity();
    const initialDay: DayDto = {
      bags: 0,
      enabled: true,
      timeEnd: '16:00',
      timeStart: '15:00',
    };

    schedule.monday = initialDay;

    const scheduleRepo = await Data.getRepository(ScheduleEntity);
    scheduleRepo.save(schedule);
  }

But when creating a shop, I get an error: EntityMetadataNotFoundError: No metadata for "ScheduleEntity" was found.

I don’t even know if it’s possible to do it this way, because there are slight doubts about it, so that when creating an entity, I would create another entity in the relationship

Answer 1

Just like @nbk mentioned your shops table has a one-to-one relationship with schedules table.

Based on your entity definition, a ShopEntity cannot exist without creating its related ScheduleEntity because ShopEntity has the foreign key constraint (@JoinColumn() decorator defines which entity is going to save the foreign key).

To fix this specific issue, you can modify your entities like this:

@Entity('shops')
export class ShopEntity{
  @PrimaryGeneratedColumn()
  id: number;

  // Remove `@JoinColumn()` decorator from this entity.
  @OneToOne(() => ScheduleEntity, (schedule) => schedule.shop)
  schedule: ScheduleEntity;
}

@Entity('schedules')
export class ScheduleEntity {
  @PrimaryGeneratedColumn()
  id: number;
    
  @Column('jsonb')
  monday: DayDto;

  // Add `@JoinColumn()` decorator to this entity.
  @OneToOne(() => ShopEntity, (shop) => shop.schedule)
  @JoinColumn()
  shop: ShopEntity
}

Now your ShopEntity can exist without first having a ScheduleEntity.

---

However, I believe you don't need to use @AfterInsert at all here. You can simply save both entities at once like below:

await shopRepo.save({
  id: 'shopID',
  // Simply add the properties of `ScheduleEntity` inside `ShopEntity` 
  // like this (don't add an `id` for `ScheduleEntity` since it will
  // be done by TypeORM automatically).
  schedule: {
    monday: {
      bags: 0,
      enabled: true,
      timeEnd: '16:00',
      timeStart: '15:00',
    },
  },
});