ValidationError：ObjectId 没有被推入数组。导致 ValidationError

Question

我是后端 Web 开发的新手，目前正在学习 数据关联...我遇到了一个对我来说似乎很严重的错误，因为我是这个主题的新手...我我正在尝试在我的 userSchema 的 postArray 中添加 Post 的 ObjectId。

当我将第一个帖子添加到特定用户时，我没有得到预期的结果。我希望将 ObjectId 推送到 postArray 但这里实际发生的事情是整个 newPost 被推入 postArray。这是遇到的第一个问题。我没有得到任何错误，但我没有得到预期的结果！

第二个是当我将另一个帖子添加到 postArray 时，它给了我一个巨大的错误，命名为 ValidationError.. 我确实花了几个小时试图修复这个错误，这可能是一个未成年人，但对我来说是一种痛苦。我的代码在下面给出，错误也在下面发布！

var mongoose = require("mongoose");

mongoose.connect("mongodb://localhost/testdatabase");

var postSchema = new mongoose.Schema({
   title: String,
   content: String
});

var Post = mongoose.model("Post", postSchema);

var userSchema =  new mongoose.Schema({
    name: String,
    email: String,
    postArray: [{
        type: mongoose.Schema.Types.ObjectId,
        ref: 'Post'
    }]
});
var User = mongoose.model("User", userSchema);

var alex = new User({
    name: "Alexander",
    email: "alexander@gmail.com"
});

alex.save();

Post.create({
    title: "I'm terribly stuck here!",
    content: "Does anyone have an idea of where I'm stuck?"
}, function(err, newPost) {
    User.findOne({name: "Alexander"}, function(err, foundUser) {
        if(err) {
            console.log(err);
        } else {
            console.log("THE NEWLY ADDED POST IS" + newPost);
            foundUser.postArray.push(newPost);
            foundUser.save(function(err, savedData) {
                if(err) {
                    console.log(err);
                } else {
                    console.log(savedData);
                }
            });
        }
    });
});

Blackdeath:~/environment/Associations $ node references.js THE NEWLY ADDED POST IS{ _id: 5a5845c180a490137330bcae, title: 'I\'m terribly stuck here!', content: 'Does anyone have an idea of where I\'m stuck?', __v: 0 } { ValidationError: User validation failed: postArray: Cast to [undefined] failed for value "[{"_id":"5a5844112d4c6512beb16846","title":"This makes me sick!","content":"I\'m stuck here..Someone save me!","__v":0}]" at path "postArray" at MongooseError.ValidationError (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/error/validation.js:27:11) at model.Document.invalidate (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:1643:32) at _init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:413:18) at init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:381:5) at model.Document.$__init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:351:3) at model.syncWrapper [as $__init] (/home/ec2-user/environment/Associations/node_modules/kareem/index.js:234:23) at model.Document.init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:319:8) at completeOne (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/query.js:1980:12) at Immediate.<anonymous> (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/query.js:1502:11) at Immediate.<anonymous> (/home/ec2-user/environment/Associations/node_modules/mquery/lib/utils.js:119:16) at runCallback (timers.js:672:20) at tryOnImmediate (timers.js:645:5) at processImmediate [as _immediateCallback] (timers.js:617:5) errors: { postArray: { ValidatorError: Cast to [undefined] failed for value "[{"_id":"5a5844112d4c6512beb16846","title":"This makes me sick!","content":"I\'m stuck here..Someone save me!","__v":0}]" at path "postArray" at MongooseError.ValidatorError (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/error/validator.js:25:11) at _init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:413:37) at init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:381:5) at model.Document.$__init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:351:3) at model.syncWrapper [as $__init] (/home/ec2-user/environment/Associations/node_modules/kareem/index.js:234:23) at model.Document.init (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/document.js:319:8) at completeOne (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/query.js:1980:12) at Immediate.<anonymous> (/home/ec2-user/environment/Associations/node_modules/mongoose/lib/query.js:1502:11) at Immediate.<anonymous> (/home/ec2-user/environment/Associations/node_modules/mquery/lib/utils.js:119:16) at runCallback (timers.js:672:20) at tryOnImmediate (timers.js:645:5) at processImmediate [as _immediateCallback] (timers.js:617:5) message: 'Cast to [undefined] failed for value "[{"_id":"5a5844112d4c6512beb16846","title":"This makes me sick!","content":"I\\\'m stuck here..Someone save me!","__v":0}]" at path "postArray"', name: 'ValidatorError', properties: [Object], kind: 'cast', path: 'postArray', value: '[{"_id":"5a5844112d4c6512beb16846","title":"This makes me sick!","content":"I\'m stuck here..Someone save me!","__v":0}]', reason: undefined } }, _message: 'User validation failed', name: 'ValidationError' }

Answer 1

发现错误..我将猫鼬包添加到package.json失败

起初，我只是这样做

npm install mongoose

后来我尝试做

npm install mongoose --save

成功了！谢谢！