我有一个服务方法，看起来像这样：

async getTeamsByNightId(id: string) {
    const night = await this.nightModel.findById({_id: id});
    console.log('night: ', night);
    //@TODO Why is populate not working?
    //const night = (await this.nightModel.findById({_id: id})).populate('teams');
    if (night) {
      const teamIds = night.teams.map((teamId) => teamId.toString());
      console.log('teamIds: ', teamIds);
      try {
        const teams = await this.teamModel.find({ _id: { $in: night.teams } }).exec();
        console.log('teams: ', teams);
      } catch (error) {
        console.log(error);
      }
      
    } else {
      throw new NotFoundException('No matching Night found');
    }
  }

字符串
它正在产生这样的输出：

Mongoose: nights.findOne({ _id: ObjectId("6552ad936a93bab2b686496d") }, {})
night:  {
  _id: new ObjectId("6552ad936a93bab2b686496d"),
  name: 'a',
  askedQuestions: [],
  teams: [ new ObjectId("6552ada76a93bab2b6864972") ],
  password: '487254',
  __v: 1
}
teamIds:  [ '6552ada76a93bab2b6864972' ]
Mongoose: teams.find({ _id: { '$in': [ ObjectId("6552ada76a93bab2b6864972") ] } }, {})
teams:  []

型
正如您所看到的，它在teams数组中有一个ObjectId，但是尝试在所有团队中查找它不会产生任何结果。
有以下模式：

import { Prop, Schema, SchemaFactory } from "@nestjs/mongoose";
import { HydratedDocument, Types } from "mongoose";
export type NightDocument = HydratedDocument<Night>;
@Schema()
export class Night {
    @Prop()
    name: string;
    @Prop()
    password: string;
    @Prop([{ type: Types.ObjectId, ref: 'Question' }])
    askedQuestions: Types.ObjectId[];
    @Prop([{ type: Types.ObjectId, ref: 'Team' }])
    teams: Types.ObjectId[];;
}
export const NightSchema = SchemaFactory.createForClass(Night);

型
和团队

import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
import { HydratedDocument, Types } from 'mongoose';
export type TeamDocument = HydratedDocument<Team>;
@Schema()
export class Team {
  @Prop()
  username: string;
  @Prop()
  password: string;
}
export const TeamSchema = SchemaFactory.createForClass(Team);

型
我将团队中的objectId添加到夜晚的方式是：

async addTeamToNight(teamId: string, addTeamToNightDTO: AddTeamToNightDTO) {
    const name = addTeamToNightDTO.name;
    const password = addTeamToNightDTO.password;
    const night = await this.nightModel.findOne({name, password}).exec();
    if (night) {
      night.teams.push(new Types.ObjectId(teamId));
      return await night.save();
    } else {
      throw new NotFoundException('Name or Password incorrect');
    }
  }

型
我做错了什么？