Mongoose - 不能在 post findOneAndUpdate 钩子中调用 model.find()

Posted 2023-03-10

【中文标题】Mongoose - 不能在 post findOneAndUpdate 钩子中调用 model.find()

【英文标题】：Mongoose - can't call model.find() in post findOneAndUpdate hook

【发布时间】：2019-12-26 02:24:29

【问题描述】：

总结

在 Mongoose 中有一个 post findOneAndUpdate 钩子，在这个钩子里面我需要查询数据库。我正在尝试在另一个模型上执行 .find()，但是每次执行时都会出现以下错误：

错误

TypeError: Users.find is not a function
    at model.Query.<anonymous> (/Users/benjilightstone/Coding/eSports-node-RESTful-API/api/models/fortniteUsers.js:29:32)

我尝试在我的一条快速路线中运行完全相同的 .find() 并且它运行良好。我已经检查了用户的 require() 并且它已正确导入。我不知道为什么会收到此错误，希望得到帮助！

代码

fortniteUsers.js（带有后挂钩的模型）

const mongoose = require("mongoose");
const Users = require("./users");
const uniqueValidator = require("mongoose-unique-validator");
const statsFieldsSchema = require("./statsFields");

const fnUserPlatformSchema = 
  //this is so that have a unique entry for a username &platform combo
  fnUser:  type: String, require: true ,
  platform:  type: String, enum: ["pc", "xb1", "psn"], require: true 
;
//TODO took out updated at because the record shouldn't get updated?
//TODO think about usecase of Fortnite user changing their username

const fortniteUserSchema = mongoose.Schema(
  // pass a javascript object that defines the schema
  fnUserPlatform:  type: fnUserPlatformSchema, unique: true, require: true ,
  createdAt:  type: Date, require: true ,
  hasAccount:  type: Boolean, require: true, default: false ,
  updatedAt:  type: Date, require: false ,
  lifeTimeStats:  type: statsFieldsSchema, require: true 
);

fortniteUserSchema.post("findOneAndUpdate", async function(fortniteUser, next) 
  try 
    console.log("inside fortniteUser post hook", typeof fortniteUser._id);
    const fnUserId = String(fortniteUser._id);
    console.log("fnUserId", fnUserId);
    // const userId = await User.find( fnUser: fnUserId );
    const userId = await Users.find( fnUser: "5ccb08198f52f40117e950b3" );
    console.log("userId", userId);
   catch (err) 
    console.log("error in post hook", err);
  
);

fortniteUserSchema.plugin(uniqueValidator);

module.exports = mongoose.model("FortniteUser", fortniteUserSchema);

users.js（在 fortniteUsers.js 中导入的用户模型）

const mongoose = require("mongoose");
const FortniteUsers = require("./fortniteUsers");
require("mongoose-type-email");

const userSchema = mongoose.Schema(
  // pass a javascript object that defines the schema
  fnUser: 
    type: mongoose.Schema.Types.ObjectId,
    ref: "FortniteUser",
    require: true
  ,
  eSportsUsername:  type: String, require: true ,
  password:  type: String, require: true, minlength: 5 ,
  email:  type: mongoose.SchemaTypes.Email, require: true, unique: true ,
  ageConfirmed:  type: Boolean, require: true ,
  createdAt:  type: Date, require: true ,
  updatedAt:  type: Date, require: false 
);

userSchema.pre("save", function() 
  console.log("inside pre save users.js");
  console.log("docToSave", this); // QUESTION:  how would I pass in req.body.fnUser
  FortniteUsers.findOne(
    fnUserPlatform:  username: req.body.fnUser, platform: "psn" 
  )
    .then(result => 
      console.log("result in pre", result);
    )
    .catch(err => console.log("error i expect", err));
);

userSchema.post("save", function(user) 
  //TODO where is user gettting passed from, I dont really understand this
  console.log("we're in post save ... ", user);

  FortniteUsers.findOneAndUpdate(
     _id: user.fnUser ,
     $set:  hasAccount: true  ,
    function(err, doc) 
      if (err) 
        console.log("error in mongoose userSchema.post", err);
      
    
  );
);

module.exports = mongoose.model("User", userSchema);

【参考方案1】：

看起来问题是因为您需要 fortniteUsers 和 users 彼此，因此在另一个内部调用时其中一个尚未导出。

要验证这一点，您可以在需要它们之后 console.log(FortniteUsers) 和 console.log(Users)。你可以看到FortniteUsers 是Model FortniteUsers 但Users 只是。

您可以通过将这一行 const FortniteUsers = require("./fortniteUsers"); 移动到 users.js 中的导出之后来解决它（不确定这是不是好方法，但它有效）。