Develop Reference

Why could the findOrCreate plugin create several documents at once?

I'm currently working on a MERN application with following/follower function for the users. I decided to create separate schemas for following and follower relationships detached from user schema.
Follower schema
const mongoose = require('mongoose');
const findOrCreate = require('mongoose-findorcreate');
const ObjectId = mongoose.Schema.Types.ObjectId;
const followerSchema = mongoose.Schema({
userId: {
type: ObjectId,
ref: 'User'
},
follower: {
type: [ObjectId],
ref: 'User'
}
});
followerSchema.plugin(findOrCreate);
const Follower = mongoose.model('Follower', followerSchema);
module.exports = { followerSchema, Follower };
Following schema
const mongoose = require('mongoose');
const findOrCreate = require('mongoose-findorcreate');
const ObjectId = mongoose.Schema.Types.ObjectId;
const followingSchema = mongoose.Schema({
userId: {
type: ObjectId,
ref: 'User'
},
following: {
type: [ObjectId],
ref: 'User'
}
});
followingSchema.plugin(findOrCreate);
const Following = mongoose.model('Following', followingSchema);
module.exports = { followingSchema, Following };
The problem however starts in my service where followings are created as supposed to. However, for followers mongoose create 6-8 documents at once with userIds that don't even exist in my db.
Here's the code of the followerService (it's the first function)
const { Follower } = require('../models/followerModel');
const { Following } = require('../models/followingModel');
const { User } = require('../models/userModel');
const mongoose = require('mongoose');
exports.changeFollowStatus = async (user, userId) => {
console.log({ userId: userId, user: user._id });
const newFollowing = await Following.findOrCreate({ userId: user._id }, (err, following, created) => {
console.log({following: following});
if (!err && !isFollowing(following, userId)) {
following.following.push(mongoose.Types.ObjectId(userId));
following.save();
User.findByIdAndUpdate(mongoose.Types.ObjectId(userId), {$inc: {follower: 1}});
} else {
const followingIndex = following.following.indexOf(mongoose.Types.ObjectId(userId));
following.following.splice(followingIndex, 1);
following.save();
User.findByIdAndUpdate(mongoose.Types.ObjectId(userId), { $inc: { follower: -1 } });
}
});
const newFollower = await Follower.findOrCreate({ userId: mongoose.Types.ObjectId(userId) }, (err, follower, created) => {
console.log({follower: follower});
if (!err && !isFollower(follower, user._id)) {
follower.follower.push(user._id);
follower.save();
User.findByIdAndUpdate(user._id, { $inc: { following: 1 } });
} else {
const followerIndex = follower.follower.indexOf(user._id);
follower.follower.splice(followerIndex, 1);
follower.save();
User.findByIdAndUpdate(user._id, { $inc: { following: -1 } });
}
});
};
exports.showFollowings = async (userId) => {
const followings = await Following.findOrCreate({ userId: mongoose.Types.ObjectId(userId) });
return followings.following;
};
exports.showFollowers = async (userId) => {
const followers = await Follower.findOrCreate({ userId: mongoose.Types.ObjectId(userId) });
return followers.follower;
};
const isFollowing = (newFollowing, userId) => {
return newFollowing.following.includes(mongoose.Types.ObjectId(userId));
};
const isFollower = (newFollower, userId) => {
return newFollower.follower.includes(userId);
}
Now, my following adding code and follower adding code look almost identical, but for some reason for followers, mongoose creates many more documents. The strange thing is that there is a follower document with the correct userId, but many other with random userIds get created which doesn't happen with followings which works as supposed to.
I also checked whether I pass the correct values and everything seems to be fine. But just for reference, here's the controller function from which I pass the values.
exports.changeFollowingStatus = async (req, res, next) => {
passport.authenticate('jwt', async (err, user, info) => {
if (err) {
console.error({ authError: err });
};
if (info !== undefined) {
console.error({ authError: info.message });
res.status(403).send(info.message);
} else {
console.log({params: req.params});
const userToFollow = req.params.id;
await FollowerService.changeFollowStatus(user, userToFollow);
res.status(200).send({ message: 'success' })
}
})(req, res, next);
};
Could anyone help me with this bug or at least navigate me towards the right direction? I can't seem to find solution to my problem. Thank you all in advance!

Insert data into MongoDb using mongoose

I have an array of strings, I want to map through this array and update my collection with it's values.
This is What I have tried:
if (employees) {
employees.map((employee) => {
Employee.updateOne({ $push: { name: employee.name } })
.then((data) => {
console.log(data);
})
.catch((e) => {
console.log(e);
});
});
}
At the top I am importing my model :
const Employee = require('../../models/employees');
My Model looks like this :
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const EmployeeSchema = new Schema({
name: { type: String },
});
const Employee = mongoose.model('employee', EmployeeSchema);
module.exports = Employee;
My console is logging the next :
{ n: 0, nModified: 0, ok: 1 }
But when i check the database the data is not there and no collection is created.

updateOne has following syntax.
First parameter is condition/filter.
Second parameter is doc to be updated.
Third is options. Where you need to pass upsert to true.
Note: If upsert is set to true then updateOne will create new doc if the filter results empty.
const insertEmployees = () => {
try {
if (employees) {
employees.map(async employee => {
let filter = { name: employee.name }
let doc = { $push: { name: employee.name } }
let options = { upsert: true }
await Employee.updateOne(filter, doc, options)
});
}
} catch (error) {
console.log(error);
}
}

How can I loop through this array inside this instance of my mongoose model?

const postSchema = new mongoose.Schema({
post:[
{postId: String},
{commentComponent: [
{comment: [String]},
]}
]
})
const Posts = mongoose.model('Posts', postSchema)
This is the definition of the schema for modeling the mongodb
const postLinks = await getPostLinks();
const posts = new Posts({
for (let i = 0; i < postLinks.length; i++) {
const comment = await getComment(postLinks[i]) // here it takes postLinks as a paramaeter to get an array of comment
post: [
{postId: postLinks[i]},
{commentComponent: [
{comment: comment}
]}
]
}
})
const result = await posts.save()
is there a way of iterating inside this instance because the for loop here is not working

You need to pass an object to the Posts constructor with a property called post (which probably should be called posts, but will keep the original name below), and for this property, you need to specify an array.
This array can be built by using Array.prototype.map and Promise.all:
const post = await Promise.all(
postLinks.map(async (postLink) => {
const comment = await getComment(postLink);
return {
postId: postLink,
commentComponent: [{ comment }],
};
})
);
const posts = new Posts({ post });
const result = await posts.save();
But if you prefer, you can use the traditional for-loop (more similar to what you were trying to do) as well:
const post = [];
for (let i = 0; i < postLinks.length; i++) {
const comment = await getComment(postLinks[i]);
post.push({
postId: postLinks[i]},
commentComponent: [{ comment }]
});
}
const posts = new Posts({ post });
const result = await posts.save();

Based on your code example I am not certain what you are attempting to do. When using a Model and trying to create you can think of as a new singular record. If you are trying to insert many links into a single record I would suggest comma separating them then inserting that into your MongoDB.
But you cannot iterate inside your Posts class like that.
If I were you I would set up my file something like this:
file: models/Post.js:
const mongoose = require('mongoose');
const PostSchema = new mongoose.Schema({
text: {
type: String,
trim: true,
required: [true, 'Please add some text']
},
link: {
type: String,
required: [true, 'Please add link']
},
createdAt: {
type: Date,
default: Date.now
}
});
module.exports = mongoose.model('Post', PostSchema);
Then create a controller js file
file: controllers/posts.js:
const Post = require('../models/Post');
// #desc Add Post
// #route POST /api/v1/posts
// #access Public
exports.addPost = async (req, res, next) => {
try {
// get post data from the request
// mongo returns a promise so await on it
const post = await Post.create(req.body);
return res.status(201).json({
success: true,
data: post
});
} catch (err) {
if(err.name === 'ValidationError') {
const messages = Object.values(err.errors).map(val => val.message);
return res.status(400).json({
success: false,
error: messages
});
} else {
return res.status(500).json({
success: false,
error: 'Server Error'
});
}
}
}
then in your router file, you can use your controller:
routes/post.js
const express = require('express');
const router = express.Router();
const { addPost } = require('../controllers/posts');
router
.route('/')
.post(addPost);
module.exports = router;

Why is this mongoose 'findOne' query always returning null?

I am trying to find a specific document with mongoose in my Cosmosdb with this query described below.
const mongoose = require('mongoose');
var ObjectID = require('mongodb').ObjectID
const keys = require('../config/keys');
const Item = mongoose.model('items');
const uploadToBlob = async (containerName, blobName, json, id) => {
console.log('id', id)
Item.findOne({ _id: id }, (foundItem) => {
console.log(foundItem)
});
console.log('here')
Item.findOneAndDelete({ name: blobName });
};
I am successfully able to find the document when querying like this below.
const scanMongo = () => {
Item.find({
_id: {
$gt: ObjectID.createFromTime(Date.now() / keys.mongoPurgeInterval)
}}, (err, foundItems) => {
if(err) {
console.log("Oops", err);
return;
}
foundItems.forEach(item => {
JSON.stringify(item)
const blobName = item.name;
json = "'"+item+"'"
const id = item._id
uploadToBlob(keys.containerName, blobName, json, id);
});
});
}
This is what the object I'm looking for looks like when pulled from the query above.
[ { _id: 5cabd5c6e16288230cba2cf6, name: 'test', value: 1, __v: 0 } ]
For kicks, here my model.
const mongoose = require('mongoose');
const { Schema } = mongoose;
const itemSchema = new Schema({
name: String,
value: Number,
});
mongoose.model('items', itemSchema);
I'm befuddled. Any help would be bawler. Thanks!!!

Yeah, the first parameter is supposed to catch the error.
Item.findOne({ _id: id }, (error, foundItem) => {
console.log(foundItem)

Update fields in object with mongoose in mongodb

I have a simple collection in mongodb.
I use mongoose.
I have users model with one field type object.
And I want change this object dynamically. But this code doesn't work, I used findByIdAndUpdate(), findById, findOne(), findOneAndUpdate().
const UsersSchema = mongoose.Schema({
likes: {}
},
{ collection: 'users' });
const Users = mongoose.model('Users', UsersSchema);
const id ="5b4c540f14f353a4b9875af4";
const thems = ['foo', 'bar'];
Users.findById(id, (err, res) => {
thems.map(item => {
if (res.like[item]) {
res.like[item] = res.like[item] + 1;
} else {
res.like[item] = 1;
}
});
res.save();
});

I believe that, for solve this problem you need to add more fields in your schema:
I created one example with this data:
const UsersSchema = new mongoose.Schema({
likes :[
{
thema:{
type: String
},
likes_amount:{
type: Number
},
_id:false
}]
});
module.exports = mongoose.model('Users', UsersSchema);
I added one user:
var newUser = new UserModel({
likes:[{
thema:'foo',
likes_amount:1
}]
});
newUser.save();
Here the code that increment the likes per thema:
const thems = ['foo', 'bar'];
const userId = "5b4d0b1a1ce6ac3153850b6a";
UserModel.findOne({_id:userId})
.then((result) => {
var userThemas = result.likes.map(item => {
return item.thema;
});
for (var i = 0; i < thems.length; i++) {
//if exists it will increment 1 like
if (userThemas.includes(thems[i])) {
UserModel.update({_id: result._id, "likes.thema" : thems[i]}, {$inc: {"likes.$.likes_amount": 1}})
.then((result) => {
console.log(result);
}).catch((err) => {
console.log(err)
});
} else {
//if doesn't exist it will create a thema with 1 like
UserModel.update({_id: result._id},
{
$addToSet: {
likes: {
$each: [{thema: thems[i], likes_amount: 1}]
}
}})
.then((result) => {
console.log(result);
}).catch((err) => {
console.log(err)
});
}
}
}).catch((err) => {
console.log(err)
});
Database result of this increment:
I hope that it can help you.