[Question] How to load relation and count entity and map it so it is not nested?

Hi, I’m wondering if its possible to map the count of an entity’s relation to a custom property.

The reason for this is I’m also trying to load another relation .loadRelationCountAndMap('script.sessions', 'script.sessions') that is removing the data count from ever appearing.

Secondly, I am trying to return a specific format of entity counts that are not nested so I can easily convert them into single series data for d3 charts without over complicated logic.

If I change the loadRelationCountAndMap to (‘script.sessionsCount’, ‘script.sessions’) I can get the session count and data will appear however it is still nested within sessions and then I am returning a ‘sessionsCount’ instead of ‘sessions’.

Maybe I am taking the wrong approach? Thanks.

Expected

[
    {
        "id": 1,
        "name": "Script Name",
        "author": {
            "id": 1,
            "username": "Username"
        },
        "data": 4,
        "users": 1
    }
]

Actual

[
    {
        "id": 1,
        "name": "Script Name",
        "author": {
            "id": 1,
            "username": "Username"
        },
        "sessions": [
            {
                "data": 4
            }
        ],
        "users": 1
    }
]

    async getCount(): Promise<Script[]> {
        return await this.scriptRepository
            .createQueryBuilder('script')
            .leftJoinAndSelect('script.author', 'author')
            .leftJoinAndSelect('script.sessions', 'sessions')
            .loadRelationCountAndMap('script.users', 'script.users')
            .loadRelationCountAndMap('script.data', 'sessions.data')
            .select('script.name')
            .addSelect('script.id')
            .addSelect('author.id')
            .addSelect('author.username')
            .getMany();
    }

@Entity()
export class Script {
    @PrimaryGeneratedColumn()
    id: number;

    @Column({ unique: true })
    name: string;

    @ManyToOne(type => User, user => user.created)
    author: User;

    @ManyToMany(type => User)
    @JoinTable()
    users: User[];

    @OneToMany(type => Session, session => session.script)
    sessions: Session[];
}

[pleerock]

don’t harm yourself and your machine and execute a separate queries

[Tyler-V]

So after many attempts, this is what I came up with that seems to product the desired output, do you see any ways to improve this or is this syntax acceptable?

    async findScriptsByAuthorId(authorId: number): Promise<any> {
        return await this.scriptRepository
            .createQueryBuilder('script')
            .leftJoin('script.author', 'author')
            .leftJoin('script.users', 'users')
            .leftJoin('script.sessions', 'sessions')
            .where('author.id = :id', { id: authorId })
            .select('script.id', 'id')
            .addSelect('script.name', 'name')
            .addSelect('script.key', 'key')
            .addSelect('script.created', 'created')
            .addSelect('COUNT(DISTINCT(users.id)) as users')
            .addSelect('COUNT(DISTINCT(sessions.id)) as sessions')
            .groupBy('script.id')
            .getRawMany();
    }

[
    {
        "id": 1,
        "name": "Script Name",
        "key": "130bbbf9-5c17-488f-8143-dba67a20d512",
        "created": "2018-05-09T14:06:08.933Z",
        "users": "1",
        "sessions": "10"
    },
    {
        "id": 2,
        "name": "Test",
        "key": "45ceb0d9-a3bc-4278-817b-4da2dc4e949b",
        "created": "2018-07-10T22:46:42.649Z",
        "users": "0",
        "sessions": "0"
    }
]

Only issue I have with it now is COUNT() is being returned as a string “10” instead of a number, are there anyways around this? Is this related to https://github.com/typeorm/typeorm/issues/1875