TypeError：无法读取 null 的属性“userID”答案

【问题标题】：TypeError: Cannot read property 'userID' of nullTypeError：无法读取 null 的属性“userID”
【发布时间】：2019-04-06 00:30:23
【问题描述】：

错误：

TypeError: 无法读取属性 'userID' of null

列出了我的UserDB.js 和profileController.js，不确定这个错误是关于什么的。当我从我的页面转换并转到 myItems(cart) 时，它会吐出这个错误。

router.get('/myItems', function(req, res, next){
res.locals.signin = req.session.signin;
var UserDB = require('../models/UserDB');
var Users = UserDB.getUser();
console.log(Users);
var LocalUser = Users.find(function (ele) {if (ele.userID === req.session.signin) {return ele;}});
if (SessionOn) {
    var UserProfiles = UserDB.GetUserProfiles();
    var LocalProfile = UserProfiles.find(function (ele) {if (ele.GetUserID() === LocalUser.userID) {return ele};});
}

res.render('myItems', {LocalUser: LocalUser, LocalProfile: LocalProfile, Session: res.locals.signin, SessionOn: SessionOn});
next()
});

-------

var mongoose = require('mongoose');
   mongoose.connect('mongodb://localhost:27017/DB');
   var Schema = mongoose.Schema;

    var userDataSchema = new Schema({
    userID: {type: String, required: true},
    password: {type: String, required: true},
    firstName: {type: String, required: true},
    lastName: {type: String, required: true},
    email: {type: String, required: true},
    city: {type: String, required: true},
    state: {type: String, required: true},
    zipCode: {type: String, required: true}

    },{collection: 'User'});

    var UserData = mongoose.model('User', userDataSchema);

    function getAllUsers(){
    try{
        return UserData.find({});
    } catch(e){
        console.log(e);
    }
    }

    function getUser(user){
    try{
        return  UserData.findOne({userID: user});

    }catch(e){
        console.log("error " + e);
    }
    }

    module.exports.getUser = getUser;
    module.exports.getAllUsers = getAllUsers;

【问题讨论】：

标签： javascript mongoose userid

【解决方案1】：

您的猫鼬模型查询函数 Users.find() 为您提供了一个对象数组因此，如果您想以您使用的方式访问它试试这样

Users.findOne({userid:xxx},callback);

如果使用 find() 方法，则必须访问数组索引

Users.find({userId:xxx},(users)=>{users[0]==neededId}

【讨论】：