Nest 使用 TypeORM 报错“Nest can't resolve dependencies of the BookService...”，如何解决？

@module({
    imports: [typeormmodule.forroot({
        type: 'mysql',
        host: 'localhost',
        port: 3306,
        username: 'root',
        password: 'root',
        database: 'root',
        entities: [__dirname + '/**/*.entity.{js,ts}'],
        synchronize: true,
        timezone: 'z',
    }), bookmodule],
})
export class appmodule { }

@module({
  imports: [typeormmodule.forfeature([bookentity])],
  controllers: [bookcontroller],
  providers: [bookservice],
  exports: [bookservice]
})
export class bookmodule { }

import { InjectRepository } from "@nestjs/typeorm";
import { Repository } from "typeorm";
import { BookEntity } from './book.entity';

@Injectable()
export class BookService {
  constructor(
    @InjectRepository(BookEntity)
    private readonly bookRepository: Repository<BookEntity>,
  ) { }

  async findAll(): Promise<BookEntity[]> {
    return await this.bookRepository.find();
  }
}