Cannot set the reference to the user document in courses mongoose - mongodb

I am currently working on a RESTful API, and I am trying to reference the users schema in the courses document such that, when a POST request gets sent to the route of the course, a course is created in the DB and has as one of its fields a reference to the user that created it. However, for the life of me, I cannot figure out why the "user" field is not appearing when I post. There seem to be quite a few of these questions here on Stack so I may just be adding to the pile, but I tried their solutions and they did not work for me
var mongoose = require('mongoose')
var Schema = mongoose.Schema
var userSchema = new Schema({
firstName: {
type: String,
required: true
},
lastName: {
type: String,
required: true
},
emailAddress: {
type: String,
required: true
},
password: {
type: String,
required: true
}
});
var CourseSchema = new Schema({
user: {type: Schema.Types.ObjectId, ref: 'User'}, //FOR some reason this is not showing up on any courses created using the
title: {
type: String,
required: true
},
description: {
type: String,
required: true
},
estimatedTime: {
type: String
},
materialsNeeded: {
type: String
}
});
var User = mongoose.model('User', userSchema);
var Course = mongoose.model('Course', CourseSchema);
module.exports = {Course, User};
Do you see anything in here that would preclude the user field from appearing when a new course is created?
I have attached some screenshots to further explain.
This first image is a screen of the currently authenticated user credentials (fake data obviously). This is the user that is sending the POST request for the new course. I would expect his information to be attached to the course (see screenshot 3)
This image shows the body of the request that is sent. You can see that the key-value pairs match what is in the CourseSchema. I would expect that the "user" field would be created once the POST request is sent.
This last image is some dummy data that is the expected result.
Thanks all for taking a look at this!

User field will not be automatically added to the course document. You have to manually set the user field in the request body itself or while creating a course.
Example of the course body to be sent:-
{
user: "userId",
title: "test",
description: "test",
estimatedTime: "test",
materialsNeeded: 1
}
Also, the result of this will not include the whole user document as you have mentioned in the expected result. It will only return the userId. However, while accessing the course you can populate the user field to get the whole user document. Example for the same
Course.find({...query}).populate("user")

Related

Express.js PUT Request not updating MongoDB

I'm working on a project that is basically a super watered down social media website.
I have a chunk done already, but I'm having some issues creating a put request to my mongodb. Basically, I want to send a put request to update a numeric value to be able to have a like counter on each post.
What I'm trying do here is send a put request with a specific post id. I'm storing the post id in a hidden text box to reference it. This is pug formatted HTML:
input.form-control(type='hidden' value=item.id id='postId' placeholder='' name='postId' required='false')
form(method='PUT' action='/update/{{post._id}}')
button(type='submit') Like
Then in my router.js file I'm basically trying to take in that id and set the likes field in the Post schema to 1 (just for testing).
router.put('/update/:id', function (req, res, next) {
let id = {
_id: ObjectID(req.params.id)
};
Post.update({_id: id}, {$set:{'likes': 1}}, (err, result) => {
if(err) {
throw err;
}
res.send('user updated sucessfully');
});
});
Here is my post schema
var mongoose = require("mongoose");
var PostSchema = new mongoose.Schema({
postText: {
type: String,
unique: false,
required: true,
trim: true
},
usernameText: {
type: String,
unique: false,
required: true,
trim: true
},
likes:{
type: Number,
unique: false,
required: false
}
});
var Post = mongoose.model("Posts", PostSchema);
module.exports = Post;
Any and all help would be highly appreciated, thank you
You can't change the ObjectId. The ObjectId is generated by MongoDB and can't be changed by the user using query functions.
If you want to assign a unique id to each user for example, then create a separate field in your schema.
You cannot change the ID
'PUT' method is not supported directly as far as I know. You need method override

One to Many model in MongoDB for a movie ticket booking app

I have been creating a movie booking app and I'm new to developing web apps. I am wondering on how to create a model for the same. For my condition, a movie can be showed in different locations. So I have given a location array in the movie model. I would also be able to sort based on locations. So I have created a location schema and a movie schema and referred the location schema inside movie schema. I'm giving the code snippet below.
Movie Schema
const movieSchema = new Schema ({
name: {
type: String,
required: true
},
language: {
type: String,
required: true
},
format : {
type: String,
enum: ["2D", "3D"],
required: true,
default:"2D"
},
rating : {
type: Number
},
location: [locationSchema]
})
Location Schema
const locationSchema = new Schema({
name: {
type: String,
}
});
I have created a post method to create a movie record in the database with express.
Post Method
const router=express.Router();
const {Movie}=require ('../models/movie');
const {Location}=require('../models/locations')
router.post('/', function (req,res) {
let body= req.body;
let movie = new Movie (body)
movie.save().then(function (movie) {
res.send(movie)
}).catch (function(err) {
res.send(err)
})
})
I have created the object as shown below to post from postman tool.
First Post Request
{
"name":"Frozen 2",
"language":"English",
"rating":4,
"location":[{
"name":"Chennai"
}, {
"name":"Bangalore"
}]
}
Another Post Request
{
"name":"Aladdin",
"language":"English",
"rating":4,
"location":[{
"name":"Bangalore"
}]
}
My first post request goes fine. But when adding a different movie entry, I am getting the "E11000 duplicate key error collection" for location as the location already exists. I dont know how to proceed further.

MongoDB joining user and likes collection based on reference ids

I am trying to create a little social network using ExpressJS and MongoDB. I have a little problem relating to likes and posts collection. I know you can embed a likes inside a posts collection, but I have decided to separate both of the collection and use reference ids so I can join them later on. The main problem I have currently is this, how do I include the likes reference on the posts collection?
Let's say my posts schema looks something like this:
const PostSchema = new Schema({
content: { type: String, required: true },
isLiked: false,
}, { timestamps: true });
and my likes schema looks something like this:
const LikeSchema = new Schema(
{
// The user who is liking the post.
user: {
type: Schema.Types.ObjectId,
ref: 'User',
required: true
},
// The post that is being liked.
question: {
type: Schema.Types.ObjectId,
ref: 'Question',
required: true
},
},
{ timestamps: true }
);
I wanna make it so that whenever I try to query the posts collection, I can also get the likes embedded in it by referencing the collection and not modifying the schema to have embedded likes in it.
An example response:
{
_id: ObjectId("test"),
content: 'A post',
isLiked: false,
likes: ["A user object here based on the `likes collection`"]
}
You have to obtain them before sending the response:
Find all the likes of that post, something similar to Like.find({ question: <postId> })
Then you can resolve the users of that likes, in the command above you can concatenate .populate('user') with the mongoose populate feature
If you are interested only to the user object and not the entire like object, you can extract resolved user: const users = likes.map(x => x.user)
Then you can add the users array to the post object and sending the final object as response

how to multi ref in mongoose

I am trying to ref two documents in one property, i have been checking the oficial documentation but i didn't get the solution...
At the moment i am trying this...
items: [{
type: mongoose.Schema.Types.ObjectId,
ref: ['items','users']
}],
In the documentation they mention refPath... but i could not populate both models... any solution for this?
// LINK TO DOCUMENTATION
https://mongoosejs.com/docs/populate.html#dynamic-ref
You don't need to pass refs in arrays. Here is the simple solution:
Mongoose Model (Report.js):
You can clearly see that I did not pass any ref to my Model but still, you can use multiple refs in post/get APIs. I will show you next.
const mongoose = require('mongoose');
const reportSchema = new mongoose.Schema({
reportFrom : {
type: mongoose.Schema.Types.ObjectId,
require: true,
},
reportTo: {
type: mongoose.Schema.Types.ObjectId,
require: true,
},
}
);
module.exports = mongoose.model("report", reportSchema);
Above "reportTo" means the Id of someone post whom the user is going to report or the id of user profile whom the user is going to report. Means "reportTo" may be an ID of User Profile or Post. So, if "reportTo" contains user Id then I have to refer to users collection but if "reportTo" contains post Id then I have to refer to posts collection. So, how I can use two refs. I will simply pass type query from postman to tell which ref to go either posts or users. See below my API request:
APIs file (reports.js)
const reports = req.query.type === "Post" ? await Report.find({reportTo: req.params.id}).populate({
path: 'reportFrom', // attribute name of Model
model: "User", // name of model from where you want to populate
select: "name profilePicture", // get only user name & profilePicture
}).populate({
path: 'reportTo', // attribute name of Model
model: "Post",
}).sort({ _id: -1 })
: req.query.type === "Profile" ? await Report.find({reportTo: req.params.id}).populate({
path: 'reportFrom', // attribute name of Model
model: "User",
select: "name profilePicture",
}).populate({
path: 'reportTo', // attribute name of Model
model: "User",
select: "name profilePicture",
})
.sort({ _id: -1 })
: null
return res.status(200).json(reports);
See the line 7 & 15, you can clearly see how I use two different refs for same attribute. In first case, reportTo is refered to Post Model & in second case reportTo is refered to User Model.

MongoDB Mongoose save object with nested objects

I'm new to MongoDB and I'm creating a simple db with Mongoose with the following models: User, Game and Players.
So, one user contains none or many games. Every game has to players, and each player refers to a user. Like this (I simplified the schemas for clarity):
const UserSchema = new Schema({
name: String,
games: [{
type: Schema.Types.ObjectId,
ref: 'game'
}]
});
const GameSchema = new Schema({
mode: Number,
players: {
type: [{
type: Schema.Types.ObjectId,
ref: 'player'
}],
required: true
}
});
const PlayerSchema = new Schema({
order: Number,
isWinner: Boolean,
user: {
type: Schema.Types.ObjectId,
ref: 'user',
required: true
}
});
So, now in the frontend I want to send a petition to the backend to create a new game for users Joe (_id:11111) and Bob (_id:22222) and so I send a POST to /api/games with the body { users: [ 11111, 22222 ] }
Now my question is, for the backend to create a new game, it also has to create 2 players. What's the best way to achieve this?
In the Game.create() method, shall I retrieve the data, create and save the players, create the game, assign the players, save the game, and also update the users and add the game ids?
I also read about Mongoose middleware, where you can set certain functions to be executed before or after some operations. So maybe it's better:
pre function before Game.create, to create the players
post function before Game.create, to update the users
This last one seems cleaner.
What's the best way? Maybe another one I have not considered?
Thanks
I would suggest you using the post and pre functions defined in the mongoose middleware. They're pretty straightforward and neat to use. It will probably solve your problem.
Here is a personal example of a problem we had; In our case, we had to assign a userId from a sequence in the database. We used the following code:
var UserSchema = new Schema({
username: { type: String, required: true, unique: true },
id: { type: String },
...
});
UserSchema.pre('save', function(next) {
let doc = this;
let id = 'userSeq'
Sequence.findByIdAndUpdate(id, { $inc : {nextSId : 1} }, function(error,data) {
if(error)
next(error)
doc.id = data.nextSId-1;
next();
})
});
My suggestion is that before you create the game, you can search for the users and add a reference to the game. If I were you, I would use the findAndModify query of mongodb to find the users or create if they do not exist yet.