无法解析 OrderService 的依赖关系。 Mongoose, NestJS

Question

I'm completely new to NestJS and I struggle with a little problem. While creating an order service to my shop, I want to get access to all my books from my database - I'm using mongoose to manage database. But while creating bookModel in my orderService, in order to get access to them, Nest return me that error.

Error: Nest can't resolve dependencies of the OrderService (OrderModel, ?). Please make sure that the argument BookModel at index [1] is available in the OrderModule context.

Potential solutions:
- If BookModel is a provider, is it part of the current OrderModule?
- If BookModel is exported from a separate @Module, is that module imported within OrderModule?
  @Module({
    imports: [ /* the Module containing BookModel */ ]
  })

Here is my order.service.ts:

@Injectable()
export class OrderService {
    constructor(@InjectModel('Order') private  orderModel:Model<Document & Order>,@InjectModel('Book') public  bookModel:Model<Document & Book>)
    {        
    }
 async getOrders() {
        ///some code
    }

    async addOrder(@Body() createOrderDto: CreateOrderDto){
        ///some code
    }
}

My order.module.ts:

@Module({
  imports: [MongooseModule.forFeature([{name:'Order',schema: OrderSchema }])],
  providers: [OrderService],
  controllers: [OrderController]
})
export class OrderModule {}

And my book.module.ts:

@Module({
  imports: [MongooseModule.forFeature([{name:'Book',schema: BookSchema }])],
  controllers: [BookController],
  providers: [BookService],
  exports:[BookService]
})
export class BookModule {}

Answer 1

The error states it pretty clearly. The OrderModule doesn't have access to the BookModel ( MongooseModule.forFeature([{name: 'Book', schema: BookSchema}]) ).You can export the MongooseModule from BookModule and add BookModule to the imports array of OrderModule to quickly resolve this.