Nest.js依赖注入报错：BookingModule无法解析HotelsRepository

报错信息 #

[Nest] 2348 - 04/11/2023, 23:08:12 ERROR [ExceptionHandler] Nest can't resolve dependencies of the BookingOrderService (BookingOrdersRepository, BookingOrderDetailRepository, ?). Please make sure that the argument HotelsRepository at index [2] is available in the BookingModule context.

问题原因 #

你在BookingOrderService的构造函数中注入了HotelsRepository，但该Repository并未在BookingModule中注册——TypeOrmModule.forFeature数组里没有包含Hotels实体，Nest无法在当前模块上下文找到对应的依赖。

解决方案 #

修改module.module.ts，在TypeOrmModule.forFeature中添加Hotels实体：

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { BookingOrderService } from '../booking/booking_order/booking_order.service';
import { BookingOrderDetailService } from '../booking/booking_order_detail/booking_order_detail.service';
import { BookingOrderDetailExtraService } from '../booking/booking_order_detail_extra/booking_order_detail_extra.service';
import { UserBreakfeastService } from '../booking/user_breakfeast/user_breakfeast.service';
import { SpecialOfferCouponsService } from '../booking/special_offer_coupons/special_offer_coupons.service';
import { SpecialOfferService } from '../booking/special_offer/special_offer.service';
import { SpecialOfferController } from '../booking/special_offer/special_offer.controller';
import { SpecialOfferCouponsController } from '../booking/special_offer_coupons/special_offer_coupons.controller';
import { UserBreakfeastController } from '../booking/user_breakfeast/user_breakfeast.controller';
import { BookingOrderDetailExtraController } from '../booking/booking_order_detail_extra/booking_order_detail_extra.controller';
import { BookingOrderDetailController } from '../booking/booking_order_detail/booking_order_detail.controller';
import { BookingOrderController } from '../booking/booking_order/booking_order.controller';
import { BookingOrderDetail } from 'output/entities/BookingOrderDetail';
import { BookingOrderDetailExtra } from 'output/entities/BookingOrderDetailExtra';
import { BookingOrders } from 'output/entities/BookingOrders';
import { UserBreakfeast } from 'output/entities/UserBreakfeast';
import { SpecialOfferCoupons } from 'output/entities/SpecialOfferCoupons';
import { SpecialOffers } from 'output/entities/SpecialOffers';
// 导入Hotels实体
import { Hotels } from 'output/entities/Hotels';

@Module({
    imports: [TypeOrmModule.forFeature([
        //FOR BOOKING
        BookingOrderDetail,
        BookingOrderDetailExtra,
        BookingOrders,
        UserBreakfeast,
        SpecialOfferCoupons,
        SpecialOffers,
        // 添加Hotels实体到Repository注册列表
        Hotels,
    ]),
    ],
    providers: [BookingOrderService, BookingOrderDetailService, BookingOrderDetailExtraService, UserBreakfeastService, SpecialOfferCouponsService, SpecialOfferService],
    controllers: [SpecialOfferController, SpecialOfferCouponsController, UserBreakfeastController, BookingOrderDetailExtraController, BookingOrderDetailController, BookingOrderController],
    exports: [],
})

export class BookingModule { }

额外优化建议 #

1. 实体关联优化：当前CreateBooking方法直接接收前端传来的Hotels实体对象，存在数据安全风险。建议改为接收hotelId，在服务中通过HotelsRepository查询对应的酒店实体后再关联保存：

// 修改CreateBooking方法参数
public async CreateBooking(
    // ...其他参数
    hotelId: number,
) {
    try {
        const boorHotel = await this.hotelService.findOne({ where: { hotelId } });
        if (!boorHotel) {
            return '酒店不存在';
        }
        await this.boorService.save({
            // ...其他字段
            boorHotel: boorHotel,
        })
    } catch (error) {
        return error.message;
    }
}

同时对应修改booking_order.controller.ts的Create方法，将@Body('boorHotel') boorHotel: Hotels改为@Body('hotelId') hotelId: number。

2. 模块拆分（可选）：如果酒店相关业务有独立的模块（比如HotelModule），可以将Hotels实体的Repository注册到HotelModule并导出，然后在BookingModule的imports中导入HotelModule，这样更符合Nest的模块化设计。

内容的提问来源于stack exchange，提问作者kucingcat