Error: Cannot query across many-to-many for property on updating

Question

I am try to update many to may relation.

export class CreateProductDto {
  @ApiProperty()
  @IsString()
  description: string;

  @ApiProperty()
  @IsString()
  name: string;

  @ApiProperty({ isArray: true })
  @IsNumber({}, { each: true })
  @IsArray()
  categoryIds: number[];
}

export class UpdateProductDto extends PartialType(CreateProductDto) {}

export class ProductsService {
  constructor(
    @InjectRepository(Product)
    private productRepository: Repository<Product>,
    private categoriesService: CategoriesService,
  ) {}

  async update(id: number, updateProductDto: UpdateProductDto) {
    let categories: Category[] = undefined;
    if (updateProductDto.categoryIds) {
      categories = await Promise.all(
        updateProductDto.categoryIds.map(
          async (id) => await this.categoriesService.findOneOrFail(id),
        ),
      );
      delete updateProductDto.categoryIds;
    }
    await this.productRepository.update(
      { id },
      { ...updateProductDto, categories },
    );
    return await this.findOneOrFail(id);
  }

  async findOneOrFail(id: number) {
    const product = await this.productRepository.findOne({ id });
    if (product) {
      return product;
    }
    throw new BadRequestException(`Product is not present`);
  }
}

@Entity()
export class Product extends BaseEntity {
  @Column()
  description: string;

  @Column()
  name: string;

  @ManyToMany(() => Category, (object) => object.products, {
    cascade: true,
    eager: true,
  })
  @JoinTable()
  categories: Category[];

}

@Entity()
export class Category extends BaseEntity {
  @Column()
  name: string;

  @ManyToMany(() => Product, (object) => object.categories)
  products: Product[];
}

Finally when i try to call ProductsService.update with this payload it

"categoryIds": [ 2 ]

i got an error like this Error: Cannot query across many-to-many for property categories

Can some please help me to update many to many

Answer 1

To solve problemes like i use.

async dummyUpdate(objetUpdateDto:ObjectUpdateDto):Promise<TypeReturn>{
const {idObjectToUpdate,colum1ToUpate,colum2ToUpate...} = objetUpdateDto;
 try{
   const objectToUpdate = await this.repositoryOfEntity.findOne(idObjectToUpdate);
   idObjectToUpdate.colum1ToUpate = colum1ToUpate;
   idObjectToUpdate.colum2ToUpate = colum2ToUpate;
   await this.repositoryOfEntity.save(objectToUpdate);
   return objectToUpdate ,

}catch(err){
    throw new ConflictException("your message"+err);
}



}

Answer 2

In your Category Entity add the relation id of Product and use save method instead of update when you update your entity.

@Entity()
export class Category extends BaseEntity {
  @Column()
  name: string;

  @ManyToMany(() => Product, (object) => object.categories)
  products: Product[];

  // Add this 

  @Column()
  productId: string;
}