Develop Reference

How to insert data into MongoDB collection?

I'm using NodeJS with Mongoose. I've two tables into db.js:
const mongoose = require('mongoose')
const UserSchema = new mongoose.Schema(
{
username: { type: String, required: true, unique: true },
email: { type: String, required: true, unique: true },
password: { type: String, required: true }
},
{ collection: 'users' }
)
const model = mongoose.model('UserSchema', UserSchema)
const AccountSchema = new mongoose.Schema(
{
username: { type: mongoose.Schema.Types.ObjectId, required: true, ref: 'hahaha' },
balance: { type: Number, required: true }
},
{ collection: 'accounts' }
)
module.exports.UserSchema = model
module.exports.AccountSchema = model
As you can see the first collection contains users (username, email, password). The second collection represents a bank account, related to a specific user. So, it has two fields: user (foreign key) and balance ($100, i.e.). First question: is my code correct to accomplish this task?
Second question: how can I insert data into the AccountSchema?
I obviously want to insert data only if the user exists into Userschema. I think that this doesn't work:
const Schema = require('./model/db')
app.post('/api/addaccount', async (req, res) => {
const { username, balance } = req.body
try {
const response = await Schema.AccountSchema.create({
username,
balance
})
console.log('User account successfully: ', response)
res.json({status : "ok"})
} catch (error) {
throw error
}
})
How can I do this?

This won't work. You've to query the User model first to check if any user exists with this username. If yes, you'll continue to store data in the Account model, if not you'll return a response something like user doesn't exist

How can I update a certain key value in all nested objects with mongoose?

I have a chat application that I'm trying to add seen functionality on it.
I'm trying to execute a query that could update all chat messages (seen) columns.
here's the schema:
const messageSchema = new mongoose.Schema({
senderId: {
type: String,
required: true
},
message: {
type: String,
required: true
},
seen: { // I'm trying to update this in all the documents !!
type: Boolean,
default: false
}
}, {timestamps: true});
const chatSchema = new mongoose.Schema({
messages: [messageSchema]
});
As you can see here, I have a seen property in the message schema (which is nested inside the chat schema)
so I just want to get a single chat, update all messages inside it and update seen column to be true
I tried that:
const messagesSeen = async (req, res) => {
const chatId = req.params.id;
await Chat.findByIdAndUpdate(
chatId,
{
$set: { 'messages.seen': true },
},
{ new: true }
)
.then((chat) => {
return res
.status(200)
.json({ chat });
})
.catch((error) => {
return res.status(500).json({ message: error.message });
});
};
but unfortunately, it didn't work
so, hope to find a solution.
thank you

You should use positional operator - $[].
await Chat.findByIdAndUpdate(
chatId,
{
$set: { "messages.$[].seen": true },
},
{
new: true
})
Working example

Check if ID exist in related mongodb collection with mongoose

I have a "Drinkers" model and a "Sodas" model which is "related" - a drinker can have drunk X amount of sodas.
The route to get the data is this
router.get('/all/:drinkerId', sodasController.getAllSodasFromDrinker)
In my sodasController, is there a way to check if :drinkerId exists in the "Drinkers" collection and if not return an error that the drinker doesn't exist, without having to require the drinkersController in the sodasController.
Right now getAllSodasFromDrinker looks like this
const Sodas = require("../models/sodas.model");
exports.getAllSodasFromDrinker = async (req, res, next) => {
try {
const id = req.params.drinkerId;
if (id.match(/^[0-9a-fA-F]{24}$/)) {
await Sodas.find({ drinker: id }).exec((err, drinkerItem) => {
if (err) {
return next(err);
}
res.json({ data: drinkerItem });
});
} else {
return next("ID is in the wrong format");
}
} catch (error) {
return next(error);
}
};
In that function, I want to check if a user exists with the applied ID.
I want to avoid having to
const Drinkers = require("../models/drinkers.model") in the sodasController
The Drinkers model:
const Schema = mongoose.Schema;
const drinkersSchema = new Schema(
{
name: {
type: String,
required: true,
},
email: {
type: String,
required: true,
unique: true,
},
sodas: {
type: Schema.Types.ObjectId,
ref: "Sodas",
},
},
{ timestamps: true }
);
The Sodas model
const Schema = mongoose.Schema;
const sodaSchema = new Schema(
{
name: {
type: String,
required: true,
},
drinker: {
type: Schema.Types.ObjectId,
ref: "Drinkers",
},
},
{ timestamps: true }
);

I would add a middleware function which validates if the drinkerId exists. If it exists, you can continue to the controller. If not, then you should throw a 404 error.
Your route:
router.get(
'/all/:drinkerId',
drinkerMiddleware.exists,
sodasController.getAllSodasFromDrinker
);
drinkerMiddleware:
exports.exists = async (req, res, next) => {
try {
const drinker await Drinker.find({ drinker: req.params.drinkerId }).exec();
if (!drinker) {
return next("Drinker not found.");
}
return next();
} catch (error) {
return next(error);
}
};

Mongoose - When returning all items from a collection (with no search param) the returned items from the collection do not contain their mongo _id

I am having a bit of an issue with Mongoose/MongoDB this afternoon. I have a situation where I need to return all items from a collection, and doing so means that I do not pass in any search params to mongoose.find().
This is the controller that handles the get all request:
exports.get_all_posts = async (req, res, next) => {
const { params } = req;
const { sortby } = params;
//Sortby param takes two arguments for now: most_recent, oldest
try {
const getAllPosts = await BlogPost.find({}, { _id: 0 });
console.log(getAllPosts);
if (!getAllPosts) throw new Error('Could not get blog posts.');
res.json({
posts: date_.sort(getAllPosts, sortby)
});
} catch (error) {
next(error);
}
};
This is particularly where I think the issue is coming from:
const getAllPosts = await BlogPost.find({}, { _id: 0 });
I am passing an empty search parameter and then removing the _id so that it doesn't throw an error telling me that I need to provide the _id.
However I still need to be able to pull in all of the posts. My items from this collection return as normal, just without their _id's.
Here is my model for the blog posts:
const mongoose = require('mongoose');
const BlogPostSchema = new mongoose.Schema({
date: {
type: Date,
required: true
},
title: {
type: String,
required: true
},
author: {
type: String,
required: true
},
likes: {
type: Number,
required: false
},
post_body: {
type: String,
required: true
},
description: {
type: String,
required: true
},
tags: [
{
type: String,
required: false
}
],
featuredImage: {
type: String,
required: false
},
draft: {
type: Boolean,
required: true
}
});
module.exports = mongoose.model('BlogPost', BlogPostSchema);
One thing to note is that I have not defined an _id. Mongoose automatically adds in the _id field before saving a schema, so I think it is okay without it, as it has been in the past.
Thanks in advance for reading and any input!

Just as Joe has commented, { _id: 0 } as the second parameter is making your query not return the _id field.
Also as he said, there should be no problem whatsoever with using find({}).
Since other than what has already been stated, I couldn't figure out any mistake in the code snippets you provided, I guess this error could be coming from somewhere else in your project.

exports.get_all_posts = async (req, res, next) => { const { params } = req; const { sortby } = params;
try { const getAllPosts = await BlogPost.find({}); console.log(getAllPosts); if (!getAllPosts) throw new Error('Could not get blog posts.'); res.json({ posts: date_.sort(getAllPosts, sortby) }); } catch (error) { next(error); } };
no need to {_id:0} in the find() method because this method retrieve all the documents in the db collection

Populate Query Options with Async Waterfall

I'm trying mongoose populate query options but i don't know why the query options doesn't work.
I have user schema:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const UserSchema = new Schema(
{
username: { type: String, required: true },
email: { type: String },
name: { type: String },
address: { type: String }
},
{ timestamps: true }
);
module.exports = mongoose.model('User', UserSchema);
and feed schema:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const FeedSchema = new Schema(
{
user: { type: Schema.ObjectId, ref: 'User' },
notes: { type: String, required: true },
trx_date: { type: Date },
status: { type: Boolean, Default: true }
},
{ timestamps: true }
);
FeedSchema.set('toObject', { getters: true });
module.exports = mongoose.model('Feed', FeedSchema);
I want to find all feed by user id, i used async waterfall like the following code:
async.waterfall([
function(callback) {
User
.findOne({ 'username': username })
.exec((err, result) => {
if (result) {
callback(null, result);
} else {
callback(err);
}
});
},
function(userid, callback) {
// find user's feed
Feed
.find({})
// .populate('user', {_id: userid._id}) <== this one also doesn't work
.populate({
path: 'user',
match: { '_id': { $in: userid._id } }
})
.exec(callback);
}
], function(err, docs) {
if (err) {
return next(err);
}
console.log(docs);
});
With above code, i got all feeds, and it seems like the query option do not work at all, did i doing it wrong ?
Any help would be appreciate.

Not sure why you are looking to match "after" population when the value of _id is what is already stored in the "user" property "before" you even populate.
As such it's really just a simple "query" condition to .find() instead:
async.waterfall([
(callback) =>
User.findOne({ 'username': username }).exec(callback),
(user, callback) => {
if (!user) callback(new Error('not found')); // throw here if not found
// find user's feed
Feed
.find({ user: user._id })
.populate('user')
.exec(callback);
}
], function(err, docs) {
if (err) {
return next(err);
}
console.log(docs);
});
Keeping in mind of course that the .findOne() is returning the whole document, so you just want the _id property in the new query. Also note that the "juggling" in the initial waterfall function is not necessary. If there is an error then it will "fast fail" to the end callback, or otherwise pass through the result where it is not. Delate "not found" to the next method instead.
Of course this really is not necessary since "Promises" have been around for some time and you really should be using them:
User.findOne({ "username": username })
.then( user => Feed.find({ "user": user._id }).populate('user') )
.then( feeds => /* do something */ )
.catch(err => /* do something with any error */)
Or indeed using $lookup where you MongoDB supports it:
User.aggregate([
{ "$match": { "username": username } },
{ "$lookup": {
"from": Feed.collection.name,
"localField": "_id",
"foreignField": "user",
"as": "feeds"
}}
]).then( user => /* User with feeds in array /* )
Which is a bit different in output, and you could actually change it to look the same with a bit of manipulation, but this should give you the general idea.
Importantly is generally better to let the server do the join rather than issue multiple requests, which increases latency at the very least.