Develop Reference

how to use find function in nodejs

const categorySchema = mongoose.Schema({
name: {
required: true,
type: String
}
});
const productSchema = mongoose.Schema({
name: {
type: String,
required: true
},
category: {
type: mongoose.Schema.Types.Mixed,
ref: "Category",
required: true
}
});
As you see above I have two models where I am using Category inside Product.
Now I want to fetch all the products by passing a particular Category or its id as _id which gets generated by default by mongodb.
Although I am achieving the desired result do this below:
const id = req.query.categoryId;//getting this from GET REQUEST
let tempProducts = [];
let products = await Product.find({});
products.forEach(product => {
if (product.category._id===id){
tempProducts.push(product);
}
});
It gets me what I want to achieve but still I want to know how to get it using "find" function. or this what I am doing is the only way.

Ok thank you all for your time. I found out the solution which is:
First of all below is my schema as Product which includes another schema named Category:
const productSchema = mongoose.Schema({
name: { type: String, required: true },
category: { type: mongoose.Schema.Types.Mixed, ref: "Category", required: true } });
And to get all the products related to a particular category,
We need to add our query inside quotes like this:
let tempProducts = [];
tempProducts = await Product.find({ "category._id": id});
This is how I achieved as I wanted and working as expected.

Node.js + Mongoose: How to use a virtual property to associate an ObjectID with the property?

I'm trying to access a MongoDB database using Node.js and Mongoose.
I created a virtual property in Schema called username. See the code that follows.
const mongoose = require("mongoose");
const User = require("../models/user");
const datatypes = ['temperature', 'humidity'];
const nodeSchema = new mongoose.Schema(
{
MACAddress: {
type: String,
required: true,
trim: true,
uppercase: true,
match: /^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})$/,
},
alias: {
type: String,
trim: true,
},
coordinates: {
type: String,
required: false,
match: /^(\-?\d+(\.\d+)?),\s*(\-?\d+(\.\d+)?)$/,
},
address: {
type: String,
required: false,
},
userID: {
type: mongoose.Types.ObjectId,
},
nodeType: {
type: String,
enum: ['router', 'node'],
default: 'node',
},
dataTypes: {
type: [String],
enum: datatypes,
required: true,
}
},
{
timestamps: true,
}
);
The virtual property is used to set the userID property. See the code that follows.
// virtual field
nodeSchema.virtual("username").set(async function (username) {
this.userID = await this.getUserID(username);
});
// methods
nodeSchema.methods = {
getUserID: function (username) {
if (!username) return null;
return User.find({username: username}).then(userDoc => userDoc[0]._id);
},
};
To add a new document to the database, I am using the following code.
const newNode = new Node(newNodeData);
newNode.save().then( (node) => {
console.log(node.userID)
}
)
The problem is this... Calling the User.find function returns a promise. Even using await (see previous code), newNode.save() saves the document in the database without the userID property.
If I change the code to the following snippet, which doesn't use promise, the userID property is saved in the database with no problem. However, this is not what I want.
// virtual field
nodeSchema.virtual("username").set(async function (username) {
let ObjectId = mongoose.Types.ObjectId;
this.userID = new ObjectId("6245e896afe465a25047302e");
});
How can I force newNode.save() to wait for the promise result before saving the document to the database?

How to populate an array of model instances inside a subdocument? MongoDB Mongoose

I have a subdocument that is nested as an array. Inside that subdocument I have references to other models. Using the .Find and .Populate methods I can receive the entire objects for single models referenced in the subdocument (check out Stop below) but not an array of model instances, Facts/Recommendations. For Facts/Recommendations I receive an array of object _ids. I can probably just take those _ids and make another query but this seems messy.
Is there a way to populate the array? Do I need to use Aggregate + $lookup? Is there a more Mongo way to restructure the Schema to simplify this?
Thank you for all and any help!
My subdocument called TourStop:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const TourStopSchema = new Schema({
stop: {
type: Schema.Types.ObjectId,
ref: 'Stop',
required:[true, 'must have a Stop'],
},
mandatory: {
type:Boolean,
default: false
},
check_in_time: {
type: Number,
default: 0
},
order: {
type:Number,
required: [true, 'Must have an order']
},
facts: [{
type: Schema.Types.ObjectId,
ref: 'Fact'
}],
recommendations: [{
type: Schema.Types.ObjectId,
ref: 'Recommendation'
}]
});
module.exports = TourStopSchema;
TourStops lives inside of Tour:
const mongoose = require('mongoose');
const TourStopSchema = require('../subdocs/tour_stop');
const Schema = mongoose.Schema;
const tourSchema = new Schema({
name: {
type:String,
required:[true,'Name is required!'],
unique: true
},
city: {
type: String,
required: [true, 'City is required!']
},
tourStops:[TourStopSchema]
});
const Tour = mongoose.model('Tour', tourSchema);
module.exports = Tour;
Stop Schema which is populated just fine.
const mongoose = require('mongoose');
const LocationSchema = require('../subdocs/location');
const ImageSchema = require('../subdocs/image');
const Schema = mongoose.Schema;
const stopSchema = new Schema({
name:{
type: String,
required:[true,'Must have a name!']
},
location:LocationSchema,
categories: {
type: [String],
default:[]
},
images:{
type:[ImageSchema],
default:[]
}
});
const Stop = mongoose.model('Stop', stopSchema);
module.exports = Stop;
And Fact Schema which is not populated correctly, instead returns an array of strings with the _ids
Fact:
const mongoose = require('mongoose');
const ImageSchema = require('../subdocs/image');
const Schema = mongoose.Schema;
const factSchema = new Schema({
stop: {
type: Schema.Types.ObjectId,
ref:'Stop',
required:[true, 'A Fact must have a Stop!'],
},
description: {
type: String,
required: [true,'A Fact must have a description!']
},
images: {
type:[ImageSchema],
default:[]
}
});
const Fact = mongoose.model('Fact', factSchema);
module.exports = Fact;
And I'm running a test to check that the schema is properly hooked up to retrieve all the attributes of a TourStop:
it('saves a full relation graph', (done) => {
User.findOne({ first_name: 'Dean' })
.populate({
// in that user find the tours property and load up all tours
path: 'tours',
// inside of all those tours, find the tourstops property and load all associated stops
populate: {
path: 'tour_stops.facts',
model: 'Fact'
},
populate: {
path: 'tour_stops.stop',
model: 'Stop'
}
})
// .populate('tours.tour_stops[0].facts')
.then((user) => {
// console.log(user.tours[0].tour_stops[0].stop);
console.log(user.tours[0].tour_stops[0]);
// console.log(Array.isArray(user.tours[0].tour_stops[0].facts))
assert(user.first_name === 'Dean' );
assert(user.tours.length === 1);
assert(user.tours[0].name === "Awesome New Tour");
assert(user.tours[0].tour_stops[0].stop.name === 'Jaffa Clock Tower');
// assert(user.tours[0])
// assert(user.blogPosts[0].title === 'JS is Great');
// assert(user.blogPosts[0].comments[0].content === 'Congrats on great post!' );
// assert(user.blogPosts[0].comments[0].user.name === 'Joe' )
done();
})
})

You can use the following code to populate tours, stop, facts and recommendations.
Note in model property, we should not give string value, but the model itself. So you need to import them to your code.
User.findOne({ first_name: "Dean" })
.populate({
path: "tours",
populate: {
path: "tourStops.stop",
model: Stop
}
})
.populate({
path: "tours",
populate: {
path: "tourStops.facts",
model: Fact
}
})
.populate({
path: "tours",
populate: {
path: "tourStops.recommendations",
model: Recommendation
}
})
.then(user => {
console.log(user);
});

How do I find if an Id is present in the array of team members (which stores user ids)?

I have this model of workspace schema in my node js project(model is displayed below)
After the user logs into my application I want to display the information of a workspace only if it is created by him or he is a team member of that workspace
I am able to find the workspaces created by the user by the following query
Workspace.find({creator:req.user._id},function(err,workspaces){
res.render('home',{
wokspacses:workspaces
});
});
similarly, I also want the workspaces in which the user is the team member
Workspace.find({creator:req.user._id},function(err,workspaces){
Workspace.find({team_member:"WHAT SHOULD I WRITE HERE"},function(err,workspaces2){
res.render('home',{
wokspacses:workspaces
wokspacses2:workspaces2
});
});
Since team_members is an array simply passing the user id is not yielding the result and workspaces2 remains empty
Thank you for your time !!
const mongoose = require('mongoose');
const workspaceSchema = mongoose.Schema({
name:{
type:String,
required:true
},
date: {
type: Date,
required: true
},
creator:{
type: Object,
ref: 'User',
required: true
},
team_member: [{ type: Object, ref: 'User' }]
});
module.exports = mongoose.model('Workspace',workspaceSchema);

Use the $in Operator.
const mongoose = require("mongoose")
const Schema = mongoose.Schema
mongoose.connect('mongodb://localhost/stackoverflow', {useNewUrlParser: true});
const workspaceSchema = new Schema({
name:{
type:String,
required:true
},
date: {
type: Date,
required: true
},
creator:{
type: Object,
ref: 'User',
required: true
},
team_member: [{ type: Object, ref: 'User' }]
});
const WorkspaceModel = mongoose.model('Workspace',workspaceSchema);
const sessionUserId = "5d330f3de87ec83f95504c44" //i.e. req.user._id;
WorkspaceModel.find({
$or:[
{ creator: sessionUserId },
{
team_member: {
$in: [sessionUserId]
}
}
]
}).exec((err, result) => {
console.log("result", result)
})

".findOneAndUpdate()" not updating database properly (Mongodb & Node.js)

I try to use .findOneAndUpdate() to update my database.
No error message, but this part of the database is not updated with new data. The embedded document competitorAnalysisTextData is still empty.
// on routes that end in /users/competitorAnalysisTextData
// ----------------------------------------------------
router.route('/users/competitorAnalysisTextData/:userName')
// update the user info (accessed at PUT http://localhost:8080/api/users/competitorAnalysisTextData)
.post(function(req, res) {
console.log('1');
// Just give instruction to mongodb to find document, change it;
// then finally after mongodb is done, return the result/error as callback.
User.findOneAndUpdate(
{ userName : req.params.userName},
{
$set:
{ "competitorAnalysis.firstObservation" : req.body.firstObservation,
"competitorAnalysis.secondObservation" : req.body.secondObservation,
"competitorAnalysis.thirdObservation" : req.body.thirdObservation,
"competitorAnalysis.brandName" : req.body.brandName,
"competitorAnalysis.productCategory" : req.body.productCategory
}
},
{ upsert: true },
function(err, user) {
// after mongodb is done updating, you are receiving the updated file as callback
console.log('2');
// now you can send the error or updated file to client
if (err)
return res.send(err);
return res.json({ message: 'User updated!' });
});
})
Update
This is my "User" Schema part:
// grab the things we need
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
// Require the crypto module for password hash
'use strict';
var crypto = require('crypto');
// create competitorAnalysisSchema
var CompetitorAnalysis = new Schema({
firstObservation: { type: String },
secondObservation: { type: String },
thirdObservation: { type: String },
brandName: { type: String },
productCategory: { type: String }
});
// create competitorAnalysisPhotoSchema
var CompetitorAnalysisPhoto = new Schema({
photo1: {type: String},
photo2: {type: String},
photo3: {type: String},
photo4: {type: String}
});
// create UserSchema
var UserSchema = new Schema({
userName: { type: String, required: true, unique: true },
email: { type: String, required: true, unique: true },
password: { type: String, required: true },
currentDemo: { type: String },
nextDemo: { type: String },
startTime: { type: String },
startLocation: { type: String },
arriveTime: { type: String },
arriveLocation: { type: String },
leaveTime: { type: String },
leaveLocation: { type: String },
competitorAnalysis: [CompetitorAnalysis],
competitorAnalysisPhoto: [CompetitorAnalysisPhoto],
created_at: Date,
updated_at: Date
});
// the schema is useless so far
// we need to create a model using it
var User = mongoose.model('User', UserSchema);
// make this available to our users in our Node applications
module.exports = User;

in javascript if you wish to update an object inside an array, you need to pick the index
var arr = [{name: "person1"},{name:"person2"}]
arr[0].name = "myname"
arr[1].name = "myFriend"
So it's the same in mongodb, check this link for detail example, or you can manually input the index, for quick hack.
User.findOneAndUpdate(
{ userName : req.params.userName},
{
$set:
{ "competitorAnalysis.0.firstObservation" : req.body.firstObservation,
"competitorAnalysis.0.secondObservation" : req.body.secondObservation,
"competitorAnalysis.0.thirdObservation" : req.body.thirdObservation,
"competitorAnalysis.0.brandName" : req.body.brandName,
"competitorAnalysis.0.productCategory" : req.body.productCategory
}
},
{ upsert: true },
function(err, user) {
// after mongodb is done updating, you are receiving the updated file as callback
console.log('2');
// now you can send the error or updated file to client
if (err)
return res.send(err);
return res.json({ message: 'User updated!' });
});
})
You should use the code above to update nested-array not to add to empty-array.
In javascript, if an array is still empty, we use .push() to add, while in mongodb the command is $push
var arr = []
arr.push({name:"person1"})