SQL error at populate ManyToMany relation.

[ghost]

Describe the bug
SQL error at populate ManyToMany relation using EntityRepository.find().

Stack trace

Error: (conn=52, no: 1054, SQLState: 42S22) Unknown column 'e0.$in' in 'where clause'
sql: select `e0`.*, `e1`.`artist_id`, `e1`.`style_id` from `artist` as `e0` left join `style_to_artist` as `e1` on `e0`.`id` = `e1`.`artist_id` where `e0`.`$in` in (?, ?, ?, ?, ?) and `e1`.`style_id` in (?, ?, ?, ?, ?, ?, ?, ?, ?, ?) group by `e0`.`id`, `e1`.`artist_id`, `e1`.`style_id` - parameters:[1,2,3,4,5,1,1,2,2,3,3,4,4,5,5]
    at Object.module.exports.createError (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/mariadb/lib/misc/errors.js:55:10)
    at PacketNodeEncoded.readError (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/mariadb/lib/io/packet.js:510:19)
    at Query.readResponsePacket (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/mariadb/lib/cmd/resultset.js:46:28)
    at PacketInputStream.receivePacketBasic (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/mariadb/lib/io/packet-input-stream.js:104:9)
    at PacketInputStream.onData (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/mariadb/lib/io/packet-input-stream.js:160:20)
    at Socket.emit (events.js:210:5)
    at Socket.EventEmitter.emit (domain.js:476:20)
    at addChunk (_stream_readable.js:308:12)
    at readableAddChunk (_stream_readable.js:289:11)
    at Socket.Readable.push (_stream_readable.js:223:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:182:23)
From previous event:
    at Client_MySQL._query (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/knex/lib/dialects/mysql/index.js:124:12)
    at Client_MySQL.query (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/knex/lib/client.js:158:17)
    at Runner.query (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/knex/lib/runner.js:135:36)
    at /home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/knex/lib/runner.js:39:23
From previous event:
    at Runner.run (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/knex/lib/runner.js:25:16)
    at Builder.Target.then (/home/alejandro/Documentos/Proyectos/tattoo/server/node_modules/knex/lib/interface.js:14:43)

To Reproduce
Steps to reproduce the behavior:

entities/artistEntity.ts

import { Collection, Entity, IdentifiedReference, IdEntity, ManyToMany, OneToOne, PrimaryKey } from "mikro-orm";
import { AccountEntity } from "./accountEntity";
import { StyleEntity } from "./styleEntity";

@Entity({ collection: "artist" })
export class ArtistEntity implements IdEntity<ArtistEntity> {
    @PrimaryKey()
    public id!: number;

    @OneToOne(() => AccountEntity)
    public account!: IdentifiedReference<AccountEntity>;

    @ManyToMany(() => StyleEntity, (style) => style.artists)
    public styles: Collection<StyleEntity>;

    public constructor() {
        this.styles = new Collection(this);
    }
}

entities/styleEntity.ts

import { Collection, Entity, IdEntity, ManyToMany, PrimaryKey, Property } from "mikro-orm";
import { ArtistEntity } from "./artistEntity";

@Entity({ collection: "style" })
export class StyleEntity implements IdEntity<StyleEntity> {
    @PrimaryKey()
    public id!: number;

    @Property()
    public name!: string;

    @ManyToMany(() => ArtistEntity)
    public artists: Collection<ArtistEntity>;

    public constructor() {
        this.artists = new Collection(this);
    }
}

stores/styleStore.ts

import { EntityRepository } from "mikro-orm";
import { inject, singleton } from "tsyringe";
import { StyleEntity } from "../entities/styleEntity";
import OrmClient from "../ormClient";

@singleton()
export default class StyleStore {
    private styleRepository: EntityRepository<StyleEntity>;

    public constructor(@inject(OrmClient) ormClient: OrmClient) {
        this.styleRepository = ormClient.em.getRepository(StyleEntity);
    }

    public async artists(artists: number[]): Promise<Array<StyleEntity | undefined>> {
        const styles = await this.styleRepository.find({ artists }, ["artists"]);

        console.log(styles[0].artists);

        return [];
        // return artists.map((artist) => styles.find((style) => style.artists.id === artist));
    }
}

Expected behavior
No SQL error.

Additional context
I have an array of artists ids: [ 1, 2, 3, 4, 5 ] and I want all styles of these artists, using only a query and I need they on same order: [[styles of artist id: 1], [styles of artist id: 2], ...].

Versions

Dependency	Version
node	v12.13.0
typescript	3.6.3
mikro-orm	3.0.0-alpha.34
your-driver	mariadb

[B4nan]

Confirmed and replicated, thanks for the detailed report!

[B4nan]

Fixed in 3.0.0-alpha.36.

[ghost]

Thanks to you for the fast resolution.