I have a Post entity:
export class Post {
@PrimaryKey()
_id!: ObjectId;
@Field(() => ID)
@SerializedPrimaryKey()
id!: string;
@Field(() => String)
@Property()
createdAt: Date = new Date();
@Field(() => String)
@Property({ onUpdate: () => new Date() })
updatedAt: Date = new Date();
@Field(() => String)
@Property()
title!: string;
@Field(() => String)
@Property()
excerpt!: string;
@Field(() => String)
@Property()
content!: string;
@Field(() => User)
@ManyToOne()
author!: User;
}
User Entity:
@ObjectType()
@Entity()
export class User {
@PrimaryKey()
_id!: ObjectId;
@Field(() => ID)
@SerializedPrimaryKey()
id!: string;
@Field(() => String)
@Property()
createdAt = new Date();
@Field(() => String)
@Property({ onUpdate: () => new Date() })
updatedAt = new Date();
@Field(() => String)
@Property()
name!: string;
@Field(() => String)
@Property({ unique: true })
email!: string;
@Property()
password!: string;
@Field(() => [Post], { nullable: true })
@OneToMany(() => Post, (post) => post.author)
posts = new Collection<Post>(this);
}
Create Post function:
@Mutation(() => Post)
async createPost(
@Arg("post") post: PostInput,
@Ctx() { em, req }: appContext
) {
const newPost = em.create(Post, {
...post,
author: new ObjectId(req.session.sid),
});
await em.persistAndFlush(newPost);
return newPost;
}
As you can see, User and Post are related with one to many relations respectively. user.posts is working correctly, as we need to add init(). But when I tried to log post.author it is giving me the following:
Ref<User> { _id: ObjectId('600663ef9ee88b1b9c63b275') }
I have searched the docs but couldn't find how to populate the author field.
To populate a relation, you can use the wrap helper:
await wrap(newPost.author).init();
If the entity would be already loaded, it would be enough to mark it as populated:
await wrap(newPost.author).populated();
(but here it is not loaded, you can tell by the Ref<> when you log it, it is there only for not loaded entities)
https://mikro-orm.io/docs/entity-helper/#wrappedentity-and-wrap-helper
If you want to have same result for loaded entities and newly persisted entities, you can use populateAfterFlush: true in the ORM config. That way, all relations will be populated after calling em.flush(). But that would also not help here, as you are working with a PK of existing entity that is not loaded (e.g. it would help when using newPost.author = new Author()).
Btw it should not be needed to use object id here, this should be fine too:
const newPost = em.create(Post, {
...post,
author: req.session.sid,
});