使用 express 和 mongoose 在 mongodb 中更新单个文档的问题

Question

我对 mongodb 很陌生，实际上我正在尝试在后端实现 follow-unfollow 方法 数据库中有两种类型的用户

导师和学员

只有被指导者可以关注导师，导师只能接受请求

架构

导师

const MentorsSchema = mongoose.Schema({
  name: { type: String, required: true },
  designation: { type: String, required: true },
  yearNdClass: {
    type: String,
    required: ["true", "year and class must be spciefied"],
  },
  respondIn: { type: String, required: true },
  tags: {
    type: [String],
    validate: (v) => v == null || v.length > 0,
  },
  socialLinks: {
    github: { type: String, default: "" },
    twitter: { type: String, default: "" },
    facebook: { type: String, default: "" },
    instagram: { type: String, default: "" },
  },
  watNum: { type: Number, required: true },
  email: { type: String, required: true, unique: true },
  password: { type: String, required: true },
  about: { type: String },
  followers: [
    { type: mongoose.Schema.Types.ObjectId, ref: "Mentees", default: "" },
  ],
  pending: [
    { type: mongoose.Schema.Types.ObjectId, ref: "Mentees", default: "" },
  ],
});

学员

const MenteeSchema = mongoose.Schema({
  name: { type: String, required: true },
  email: { type: String, required: true, unique: true },
  password: { type: String, required: true },
  yearNdClass: {
    type: String,
    required: ["true", "year and class must be spciefied"],
  },
  socialLinks: {
    github: { type: String },
    twitter: { type: String },
    facebook: { type: String },
    instagram: { type: String },
  },
  about: { type: String },
  skillLooksFor: { type: String, required: true },
  watNum: { type: Number, required: true },
  following: [{ type: mongoose.Schema.Types.ObjectId, ref: "Mentors",default:"" },
  
],
});

您可以看到导师有两个字段，分别是跟随和待定数组，其中包括跟随导师的被指导者的 ID 和尚未被接受为跟随者的被指导者的 ID

我计划创建一个端点，当被指导者发出关注请求时，应该将其连接到指导者待处理数组中，以便他以后可以接受它

所以我的逻辑是这样的

// @desc follow a mentor
// @route POST /api/mentees/follow-mentor/:id
// @access private

menteeRoute.post(
  "/follow-mentor/:id",
  isAuthorisedMentee,
  expressAsyncHandler(async (req, res) => {
    const { id } = req.params;
    const mentee = await Mentees.findById(req.mentee.id);
    const mentor = await Mentors.findById(id).select("-password");
    // console.log(mentor)
    if (mentee) {
      try {
        await Mentees.findOneAndUpdate(
          { _id: mongoose.Types.ObjectId(id) },
          { $addToSet: { "following.0": mentor._id } },
          { new: true }
        );

        await Mentors.findOneAndUpdate(
          { _id: mongoose.Types.ObjectId(mentor._id) },
          {
            $addToSet: {
              "pending.0": id,
            },
          },
          { new: true },
        );

        res.json({
          data: {
            mentor,
            mentee,
          },
        });
      } catch (error) {
        console.log(error);
        throw new Error(error);
      }
    }
  })
);

但代码不起作用。 谁能帮我解决这个问题？

基本上，当学员发出关注请求时，它应该用id of mentor 更新mentee 的following 数组，它还应该用 mentor 更新 pending 数组id of the mentee

PS：也欢迎任何替代想法

Answer 1

尝试删除.0 索引并使用$push 方法。
此外，您应该返回更新的对象：

menteeRoute.post(
  '/follow-mentor/:id',
  isAuthorisedMentee,
  expressAsyncHandler(async (req, res) => {
    const { id } = req.params;
    const mentee = await Mentees.findById(req.mentee.id);
    const mentor = await Mentors.findById(id).select('-password');
    // console.log(mentor)
    if (mentee) {
      try {
        const updatedMentee = await Mentees.findOneAndUpdate(
          { _id: mongoose.Types.ObjectId(id) },
          { $push: { following: mentor._id } },
          { new: true }
        );

        const updatedMentor = await Mentors.findOneAndUpdate(
          { _id: mentor._id },
          {
            $push: {
              pending: id,
            },
          },
          { new: true }
        );

        res.json({
          data: {
            mentor: updatedMentor,
            mentee: updatedMentee,
          },
        });
      } catch (error) {
        console.log(error);
        throw new Error(error);
      }
    }
  })
);