TypeORM Cannot query across one-to-many for property error

Hi all,

I have the following two entities:

import { Entity, Column, PrimaryGeneratedColumn, ManyToOne } from "typeorm";

import { Activity } from "./";

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

    @Column({unique: false,nullable: false})
    name: string;

    @Column({type: "float",unique: false,nullable: false})
    price: number;
    
    @ManyToOne(() => Activity, activity => activity.fares)
    activity: Activity;
}

and

import { Entity, Column, OneToMany, PrimaryGeneratedColumn } from "typeorm";

import { Fare } from "./";

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

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

    @Column({unique: false,nullable: true})
    description: string;
    
    @OneToMany(() => Fare, (fare) => fare.activity, {cascade: true})
    fares: Fare[];
}

and I want to update an activity using the following body:

{"id":10, "name":"dddd", "fares":[{"id":5,"name":"jeune","price":20.0}]}

To do so, I implemented the following service:

import { singleton } from 'tsyringe'
import { getConnection, Timestamp } from 'typeorm';

import { Activity } from '../entities/';
import { ActivityRepository } from '../repositories'

import { Fare } from '../entities'

@singleton()
export class ActivityService {

    constructor(private _activityRepository: ActivityRepository) {
        this._activityRepository = getConnection("lasso").getCustomRepository(ActivityRepository);
    }
            
    public update = async (activity: Activity, id: number) => {
        const updatedActivity = await this._activityRepository
            .createQueryBuilder()
            .update(Activity)
            .set(activity)
            .where("id = :id", { id: id })
            .execute();
        return updatedActivity;
    }
};

When running my update request I get the following error:

(node:204854) UnhandledPromiseRejectionWarning: Error: Cannot query across one-to-many for property fares From a previous related issue, the answer was to use query builder for such tasks. Does it mean that the way I did it is wrong ? Could you please show me what is wrong with my query ?