Why won't this simple TypeORM query return my ManyToOne property with PostgreSQL?-CodePudding

In my database, I have one species record and two cat records

Cat Table

id   size   species_id
1    large   5
1    small   5

Species Table

id 
5

@Entity('cat')
export class Cat {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @Column({ type: 'text' })
  size: string;

  @ManyToOne(() => Species)
  @JoinColumn({ name: 'species_id', referencedColumnName: 'id' })
  speciesId: string;

}

@Entity('species')
export class Species {
  @PrimaryGeneratedColumn('uuid')
  id: string;

}

const entity = await this.catRepository.findOneOrFail(catId);

the entity only returns {id: catId, size: 'large'} but does not return the speciesId even though there's a species id in the cat record in my database.

I am new to TypeORM and I think one of the things ManyToOne does is to establish FK constraints. Why is the query behavior the way it is and how can I get the species id to return without having to use joins?

CodePudding user response：

In your situation I think you are missing 1 extra column in Cat entity. Column in which you will store species_id, or if you wish to make it accurate, then use singular specie_id.

@Entity('cat')
export class Cat {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @Column({ type: 'text' })
  size: string;

  @Column({type: 'uuid' })
  specie_id: string;

  @ManyToOne(() => Species)
  @JoinColumn({ name: 'specie_id', referencedColumnName: 'id' })
  species: Species;

}

More info you can find in typeorm documentation: https://typeorm.io/#/many-to-one-one-to-many-relations