.find() with populate uses the wrong fieldNames

[quazeenii]

Hi,

I have tried searching though I wasn't sure how to word it exactly, I apologize if this was already discussed. I believe my issues is similar to this one.

I have two entities, e.g. Questions and Answers.

@Entity({ tableName: 'questions' })
export class Question {
  [PrimaryKeyType]?: [string, Date];

  @PrimaryKey({ columnType: 'uuid', defaultRaw: `gen_random_uuid()` })
  id: UUID = UUID();

  @PrimaryKey({ length: 6, defaultRaw: `now()` })
  createdAt: Date = new Date();

  @Property({ length: 6, defaultRaw: `now()`, onUpdate: () => new Date() })
  updatedAt: Date = new Date();

  @OneToMany(() => Answer, (answer) => answer.question)
  answers: Collection<Answer> = new Collection<Answer>(this);

  @Property({ length: 255 })
  name: string;
}

@Entity({ tableName: 'answers' })
export class Answer {
  [PrimaryKeyType]?: [string, Date];

  @PrimaryKey({ columnType: 'uuid', defaultRaw: `gen_random_uuid()` })
  id: UUID = UUID();

  @PrimaryKey({ length: 6, defaultRaw: `now()` })
  createdAt: Date = new Date();

  @Property({ length: 6, defaultRaw: `now()`, onUpdate: () => new Date() })
  updatedAt: Date = new Date();

  @ManyToOne({ entity: () => Question })
  question: Question;
}

in the db, Answer.question actually maps to answers.question_id and answers.question_created_at since questions has a multi-pkey that answers need to store

finding many fails when I do a find with the populate,

await this.em.find(Answer, { question }, { populate: ['question'] })

because the where clause looks for questions.question_id and questions.question_created_at instead of either questions.id and questions.created_at or answers.question_id and answers.question_created_at

where ("questions"."question_id", "questions"."question_created_at") = ('0956160c-87cf-44d3-b27e-9b24034d1c24', '2022-11-13T05:00:39.994Z') order by "answers"."created_at" desc

but it works without the populate (question just isn't populated)

await this.em.find(Answer, { question })

and it works if I use queryBuilder instead

const answers = await this.em.createQueryBuilder(Answer).where({question}).getResult()
await em.populate(answers, ['question'])

I was wondering if I was doing something wrong or if I'm supposed to just use queryBuilder?
is one better than the other? queryBuilder vs find?

[B4nan]

Can you compile this into a complete script I can run myself? As in https://github.com/mikro-orm/mikro-orm/tree/master/tests/issues

but it works without the populate (question just isn't populated)

The query that fails is the populate query - no populate hint -> no populate queries. If you do await em.populate(answers, ['question']) that would be equivalent and it will probably fail the same.

Generally speaking, I would discourage this - it only adds complexity to the entities, your UUID is unique on its own, so you don't need a composite PK here. On the other hand, its a matter of preference, and it should work, especially if it works with the QB + em.populate.

edit: now I see you do await this.em.find(Answer, { question }, { populate: ['Question'] }), that populate hint is wrong. you need to put there a property name, not entity name. this wont even type check. but I guess thats a typo in your code here, rather than in your actual app?

[B4nan]

Or well, why do you think it should be even undefined? The property represents a real database column, the foreign key - the value is there even without population. It will be represented as an entity instance.

https://mikro-orm.io/docs/next/entity-manager#entity-references

[quazeenii]

oh no, I just wasn't expecting it to be there since I didn't have the populate, I guess I assumed you would just ignore the relations. your links make sense I think, I'll have to look at it more in a bit.

but then I think there's still an issue when using LoadStrategy.JOINED which is shown in the test. unless you don't think so, then can you explain why and what I should do instead?

[B4nan]

Yes, it is indeed valid, looking into it now.

[B4nan]

Here you go, it was easier than expected. Dev version will be available in few minutes.

dec4c9c

[quazeenii]

thanks!