Develop Reference

MongoDB findOne using $and & $elemMatch not working?

I am trying to check if there is an existing conversation between two users before creating another one.
My Conversation object stores the conversation participants in an array, I need to return a conversation object that has BOTH participants (senderId & recId) that exists in my database but I am unable to build to correct MongoDB query to get it.
Please see the queries I have tried below because I have tried all manner of using $and & $elemMatch but can't get it to work.
Thank you
Conversation Model
const conversationSchema = mongoose.Schema(
{
participants: [participantSchema],
},
{timestamps: true}
)
const participantSchema = mongoose.Schema(
{
userId: {
type: mongoose.Schema.Types.ObjectId,
required: true,
ref: `User`,
},
username: {
type: String,
required: true,
}
}
)
Conversation Object
{
_id: 61cb6316asas4b54e09168234,
participants: [
{
userId: 61b777ea6815a69a625b,
username: 'johnsmith'
},
{
userId: 61bc0dcbe7181ccfd806,
username: 'testuser'
}
],
createdAt: 2021-12-28T19:18:46.673Z,
updatedAt: 2021-12-28T23:41:12.364Z
}
Queries I have tried that ARE NOT what I need or don't work
// null - no convo found when the convo definitely exists in db
const existingConvo = await Conversation.findOne({
$and: [{ userId: senderId }, { userId: recId }],
})
// works but only checks for ONE id property
// if I make an array: "Query filter must be an object, got an array"
const existingConvo = await Conversation.findOne({
participants: { $elemMatch: { userId: senderId } },
})
// "Unknown operator $and"
const existingConvo = await Conversation.find({
participants: {
$and: [{ userId: senderId }],
},
})
// returns empty array when it should have the convo object
const existingConvo = await Conversation.find({
participants: { $all: [{ userId: senderId }, { userId: recId }] },
})

How to set default value in mongoose Schema

For example, I have a schema as below.
const packSchema = new mongoose.Schema({
company: [
name: {type: String},
realName: {type: String, default: ''}
]
})
So I can save a JSON data as below.
[{
"name": "abc",
"realName": "efg"
}]
But when the data doesn't have realName, I want that realName gets data from his own name.
For example, I request this array from ajax call,
[{
"name": "KA"
},
{
"name": "MC"
}]
when I save this object, the result in mongoDB is as below.
[{
"name": "KA",
"realName": "KA"
},
{
"name": "MC",
"realName": "MC"
}]
I think the solution using 'set' option in schema.
function duplicate(){
}
const packSchema = new mongoose.Schema({
company: [
name: {type: String},
realName: {type: String, set: duplicate}
]
})
But I don't know how it can get 'name' data from his own element of array.
Should I use 'for' loop this? or is there other solution?
Thank you for reading it.

The this inside of your function will get bound to the object which you're creating. As a result, you'll be able to use:
function duplicate(v){
return v === undefined ? this.name : v;
}
Above, if the value for realName (ie: v) is undefined, then you'll return this.name, which is the name of the object you're inserting/creating. Otherwise, if realName is already set, it will use that value.

Convert company into sub schema and use a pre save hook to update realname
const companySchema = mongoose.Schema({
name: String,
realName: String
})
companySchema.pre('save',function(next) {
if(!this.realName)
this.realName = this.name
next();
})
const packSchema = mongoose.Schema({
company: [companySchema]
})
const Pack = mongoose.model('Pack', packSchema);

Working with nested arrays in MongoDB and Mongoose [duplicate]

Basically I have a mongodb collection called 'people'
whose schema is as follows:
people: {
name: String,
friends: [{firstName: String, lastName: String}]
}
Now, I have a very basic express application that connects to the database and successfully creates 'people' with an empty friends array.
In a secondary place in the application, a form is in place to add friends. The form takes in firstName and lastName and then POSTs with the name field also for reference to the proper people object.
What I'm having a hard time doing is creating a new friend object and then "pushing" it into the friends array.
I know that when I do this via the mongo console I use the update function with $push as my second argument after the lookup criteria, but I can't seem to find the appropriate way to get mongoose to do this.
db.people.update({name: "John"}, {$push: {friends: {firstName: "Harry", lastName: "Potter"}}});

Assuming, var friend = { firstName: 'Harry', lastName: 'Potter' };
There are two options you have:
Update the model in-memory, and save (plain javascript array.push):
person.friends.push(friend);
person.save(done);
or
PersonModel.update(
{ _id: person._id },
{ $push: { friends: friend } },
done
);
I always try and go for the first option when possible, because it'll respect more of the benefits that mongoose gives you (hooks, validation, etc.).
However, if you are doing lots of concurrent writes, you will hit race conditions where you'll end up with nasty version errors to stop you from replacing the entire model each time and losing the previous friend you added. So only go to the latter when it's absolutely necessary.

The $push operator appends a specified value to an array.
{ $push: { <field1>: <value1>, ... } }
$push adds the array field with the value as its element.
Above answer fulfils all the requirements, but I got it working by doing the following
var objFriends = { fname:"fname",lname:"lname",surname:"surname" };
People.findOneAndUpdate(
{ _id: req.body.id },
{ $push: { friends: objFriends } },
function (error, success) {
if (error) {
console.log(error);
} else {
console.log(success);
}
});
)

Another way to push items into array using Mongoose is- $addToSet, if you want only unique items to be pushed into array. $push operator simply adds the object to array whether or not the object is already present, while $addToSet does that only if the object is not present in the array so as not to incorporate duplicacy.
PersonModel.update(
{ _id: person._id },
{ $addToSet: { friends: friend } }
);
This will look for the object you are adding to array. If found, does nothing. If not, adds it to the array.
References:
$addToSet
MongooseArray.prototype.addToSet()

Use $push to update document and insert new value inside an array.
find:
db.getCollection('noti').find({})
result for find:
{
"_id" : ObjectId("5bc061f05a4c0511a9252e88"),
"count" : 1.0,
"color" : "green",
"icon" : "circle",
"graph" : [
{
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 2.0
}
],
"name" : "online visitor",
"read" : false,
"date" : ISODate("2018-10-12T08:57:20.853Z"),
"__v" : 0.0
}
update:
db.getCollection('noti').findOneAndUpdate(
{ _id: ObjectId("5bc061f05a4c0511a9252e88") },
{ $push: {
graph: {
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 3.0
}
}
})
result for update:
{
"_id" : ObjectId("5bc061f05a4c0511a9252e88"),
"count" : 1.0,
"color" : "green",
"icon" : "circle",
"graph" : [
{
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 2.0
},
{
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 3.0
}
],
"name" : "online visitor",
"read" : false,
"date" : ISODate("2018-10-12T08:57:20.853Z"),
"__v" : 0.0
}

First I tried this code
const peopleSchema = new mongoose.Schema({
name: String,
friends: [
{
firstName: String,
lastName: String,
},
],
});
const People = mongoose.model("person", peopleSchema);
const first = new Note({
name: "Yash Salvi",
notes: [
{
firstName: "Johnny",
lastName: "Johnson",
},
],
});
first.save();
const friendNew = {
firstName: "Alice",
lastName: "Parker",
};
People.findOneAndUpdate(
{ name: "Yash Salvi" },
{ $push: { friends: friendNew } },
function (error, success) {
if (error) {
console.log(error);
} else {
console.log(success);
}
}
);
But I noticed that only first friend (i.e. Johhny Johnson) gets saved and the objective to push array element in existing array of "friends" doesn't seem to work as when I run the code , in database in only shows "First friend" and "friends" array has only one element !
So the simple solution is written below
const peopleSchema = new mongoose.Schema({
name: String,
friends: [
{
firstName: String,
lastName: String,
},
],
});
const People = mongoose.model("person", peopleSchema);
const first = new Note({
name: "Yash Salvi",
notes: [
{
firstName: "Johnny",
lastName: "Johnson",
},
],
});
first.save();
const friendNew = {
firstName: "Alice",
lastName: "Parker",
};
People.findOneAndUpdate(
{ name: "Yash Salvi" },
{ $push: { friends: friendNew } },
{ upsert: true }
);
Adding "{ upsert: true }" solved problem in my case and once code is saved and I run it , I see that "friends" array now has 2 elements !
The upsert = true option creates the object if it doesn't exist. default is set to false.
if it doesn't work use below snippet
People.findOneAndUpdate(
{ name: "Yash Salvi" },
{ $push: { friends: friendNew } },
).exec();

An easy way to do that is to use the following:
var John = people.findOne({name: "John"});
John.friends.push({firstName: "Harry", lastName: "Potter"});
John.save();

In my case, I did this
const eventId = event.id;
User.findByIdAndUpdate(id, { $push: { createdEvents: eventId } }).exec();

Push to nested field - use a dot notation
For anyone wondering how to push to a nested field when you have for example this Schema.
const UserModel = new mongoose.schema({
friends: {
bestFriends: [{ firstName: String, lastName: String }],
otherFriends: [{ firstName: String, lastName: String }]
}
});
You just use a dot notation, like this:
const updatedUser = await UserModel.update({_id: args._id}, {
$push: {
"friends.bestFriends": {firstName: "Ima", lastName: "Weiner"}
}
});

This is how you could push an item - official docs
const schema = Schema({ nums: [Number] });
const Model = mongoose.model('Test', schema);
const doc = await Model.create({ nums: [3, 4] });
doc.nums.push(5); // Add 5 to the end of the array
await doc.save();
// You can also pass an object with `$each` as the
// first parameter to use MongoDB's `$position`
doc.nums.push({
$each: [1, 2],
$position: 0
});
doc.nums;

// This is the my solution for this question.
// I want to add new object in worKingHours(array of objects) -->
workingHours: [
{
workingDate: Date,
entryTime: Date,
exitTime: Date,
},
],
// employeeRoutes.js
const express = require("express");
const router = express.Router();
const EmployeeController = require("../controllers/employeeController");
router
.route("/:id")
.put(EmployeeController.updateWorkingDay)
// employeeModel.js
const mongoose = require("mongoose");
const validator = require("validator");
const employeeSchema = new mongoose.Schema(
{
name: {
type: String,
required: [true, "Please enter your name"],
},
address: {
type: String,
required: [true, "Please enter your name"],
},
email: {
type: String,
unique: true,
lowercase: true,
required: [true, "Please enter your name"],
validate: [validator.isEmail, "Please provide a valid email"],
},
phone: {
type: String,
required: [true, "Please enter your name"],
},
joiningDate: {
type: Date,
required: [true, "Please Enter your joining date"],
},
workingHours: [
{
workingDate: Date,
entryTime: Date,
exitTime: Date,
},
],
},
{
toJSON: { virtuals: true },
toObject: { virtuals: true },
}
);
const Employee = mongoose.model("Employee", employeeSchema);
module.exports = Employee;
// employeeContoller.js
/////////////////////////// SOLUTION IS BELOW ///////////////////////////////
// This is for adding another day, entry and exit time
exports.updateWorkingDay = async (req, res) => {
const doc = await Employee.findByIdAndUpdate(req.params.id, {
$push: {
workingHours: req.body,
},
});
res.status(200).json({
status: "true",
data: { doc },
});
};
https://www.youtube.com/watch?v=gtUPPO8Re98

I ran into this issue as well. My fix was to create a child schema. See below for an example for your models.
---- Person model
const mongoose = require('mongoose');
const SingleFriend = require('./SingleFriend');
const Schema = mongoose.Schema;
const productSchema = new Schema({
friends : [SingleFriend.schema]
});
module.exports = mongoose.model('Person', personSchema);
***Important: SingleFriend.schema -> make sure to use lowercase for schema
--- Child schema
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const SingleFriendSchema = new Schema({
Name: String
});
module.exports = mongoose.model('SingleFriend', SingleFriendSchema);

How To Save Nested Document Objects in MongoDB [duplicate]

Basically I have a mongodb collection called 'people'
whose schema is as follows:
people: {
name: String,
friends: [{firstName: String, lastName: String}]
}
Now, I have a very basic express application that connects to the database and successfully creates 'people' with an empty friends array.
In a secondary place in the application, a form is in place to add friends. The form takes in firstName and lastName and then POSTs with the name field also for reference to the proper people object.
What I'm having a hard time doing is creating a new friend object and then "pushing" it into the friends array.
I know that when I do this via the mongo console I use the update function with $push as my second argument after the lookup criteria, but I can't seem to find the appropriate way to get mongoose to do this.
db.people.update({name: "John"}, {$push: {friends: {firstName: "Harry", lastName: "Potter"}}});

Assuming, var friend = { firstName: 'Harry', lastName: 'Potter' };
There are two options you have:
Update the model in-memory, and save (plain javascript array.push):
person.friends.push(friend);
person.save(done);
or
PersonModel.update(
{ _id: person._id },
{ $push: { friends: friend } },
done
);
I always try and go for the first option when possible, because it'll respect more of the benefits that mongoose gives you (hooks, validation, etc.).
However, if you are doing lots of concurrent writes, you will hit race conditions where you'll end up with nasty version errors to stop you from replacing the entire model each time and losing the previous friend you added. So only go to the latter when it's absolutely necessary.

The $push operator appends a specified value to an array.
{ $push: { <field1>: <value1>, ... } }
$push adds the array field with the value as its element.
Above answer fulfils all the requirements, but I got it working by doing the following
var objFriends = { fname:"fname",lname:"lname",surname:"surname" };
People.findOneAndUpdate(
{ _id: req.body.id },
{ $push: { friends: objFriends } },
function (error, success) {
if (error) {
console.log(error);
} else {
console.log(success);
}
});
)

Another way to push items into array using Mongoose is- $addToSet, if you want only unique items to be pushed into array. $push operator simply adds the object to array whether or not the object is already present, while $addToSet does that only if the object is not present in the array so as not to incorporate duplicacy.
PersonModel.update(
{ _id: person._id },
{ $addToSet: { friends: friend } }
);
This will look for the object you are adding to array. If found, does nothing. If not, adds it to the array.
References:
$addToSet
MongooseArray.prototype.addToSet()

Use $push to update document and insert new value inside an array.
find:
db.getCollection('noti').find({})
result for find:
{
"_id" : ObjectId("5bc061f05a4c0511a9252e88"),
"count" : 1.0,
"color" : "green",
"icon" : "circle",
"graph" : [
{
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 2.0
}
],
"name" : "online visitor",
"read" : false,
"date" : ISODate("2018-10-12T08:57:20.853Z"),
"__v" : 0.0
}
update:
db.getCollection('noti').findOneAndUpdate(
{ _id: ObjectId("5bc061f05a4c0511a9252e88") },
{ $push: {
graph: {
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 3.0
}
}
})
result for update:
{
"_id" : ObjectId("5bc061f05a4c0511a9252e88"),
"count" : 1.0,
"color" : "green",
"icon" : "circle",
"graph" : [
{
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 2.0
},
{
"date" : ISODate("2018-10-24T08:55:13.331Z"),
"count" : 3.0
}
],
"name" : "online visitor",
"read" : false,
"date" : ISODate("2018-10-12T08:57:20.853Z"),
"__v" : 0.0
}

First I tried this code
const peopleSchema = new mongoose.Schema({
name: String,
friends: [
{
firstName: String,
lastName: String,
},
],
});
const People = mongoose.model("person", peopleSchema);
const first = new Note({
name: "Yash Salvi",
notes: [
{
firstName: "Johnny",
lastName: "Johnson",
},
],
});
first.save();
const friendNew = {
firstName: "Alice",
lastName: "Parker",
};
People.findOneAndUpdate(
{ name: "Yash Salvi" },
{ $push: { friends: friendNew } },
function (error, success) {
if (error) {
console.log(error);
} else {
console.log(success);
}
}
);
But I noticed that only first friend (i.e. Johhny Johnson) gets saved and the objective to push array element in existing array of "friends" doesn't seem to work as when I run the code , in database in only shows "First friend" and "friends" array has only one element !
So the simple solution is written below
const peopleSchema = new mongoose.Schema({
name: String,
friends: [
{
firstName: String,
lastName: String,
},
],
});
const People = mongoose.model("person", peopleSchema);
const first = new Note({
name: "Yash Salvi",
notes: [
{
firstName: "Johnny",
lastName: "Johnson",
},
],
});
first.save();
const friendNew = {
firstName: "Alice",
lastName: "Parker",
};
People.findOneAndUpdate(
{ name: "Yash Salvi" },
{ $push: { friends: friendNew } },
{ upsert: true }
);
Adding "{ upsert: true }" solved problem in my case and once code is saved and I run it , I see that "friends" array now has 2 elements !
The upsert = true option creates the object if it doesn't exist. default is set to false.
if it doesn't work use below snippet
People.findOneAndUpdate(
{ name: "Yash Salvi" },
{ $push: { friends: friendNew } },
).exec();

An easy way to do that is to use the following:
var John = people.findOne({name: "John"});
John.friends.push({firstName: "Harry", lastName: "Potter"});
John.save();

In my case, I did this
const eventId = event.id;
User.findByIdAndUpdate(id, { $push: { createdEvents: eventId } }).exec();

Push to nested field - use a dot notation
For anyone wondering how to push to a nested field when you have for example this Schema.
const UserModel = new mongoose.schema({
friends: {
bestFriends: [{ firstName: String, lastName: String }],
otherFriends: [{ firstName: String, lastName: String }]
}
});
You just use a dot notation, like this:
const updatedUser = await UserModel.update({_id: args._id}, {
$push: {
"friends.bestFriends": {firstName: "Ima", lastName: "Weiner"}
}
});

This is how you could push an item - official docs
const schema = Schema({ nums: [Number] });
const Model = mongoose.model('Test', schema);
const doc = await Model.create({ nums: [3, 4] });
doc.nums.push(5); // Add 5 to the end of the array
await doc.save();
// You can also pass an object with `$each` as the
// first parameter to use MongoDB's `$position`
doc.nums.push({
$each: [1, 2],
$position: 0
});
doc.nums;

// This is the my solution for this question.
// I want to add new object in worKingHours(array of objects) -->
workingHours: [
{
workingDate: Date,
entryTime: Date,
exitTime: Date,
},
],
// employeeRoutes.js
const express = require("express");
const router = express.Router();
const EmployeeController = require("../controllers/employeeController");
router
.route("/:id")
.put(EmployeeController.updateWorkingDay)
// employeeModel.js
const mongoose = require("mongoose");
const validator = require("validator");
const employeeSchema = new mongoose.Schema(
{
name: {
type: String,
required: [true, "Please enter your name"],
},
address: {
type: String,
required: [true, "Please enter your name"],
},
email: {
type: String,
unique: true,
lowercase: true,
required: [true, "Please enter your name"],
validate: [validator.isEmail, "Please provide a valid email"],
},
phone: {
type: String,
required: [true, "Please enter your name"],
},
joiningDate: {
type: Date,
required: [true, "Please Enter your joining date"],
},
workingHours: [
{
workingDate: Date,
entryTime: Date,
exitTime: Date,
},
],
},
{
toJSON: { virtuals: true },
toObject: { virtuals: true },
}
);
const Employee = mongoose.model("Employee", employeeSchema);
module.exports = Employee;
// employeeContoller.js
/////////////////////////// SOLUTION IS BELOW ///////////////////////////////
// This is for adding another day, entry and exit time
exports.updateWorkingDay = async (req, res) => {
const doc = await Employee.findByIdAndUpdate(req.params.id, {
$push: {
workingHours: req.body,
},
});
res.status(200).json({
status: "true",
data: { doc },
});
};
https://www.youtube.com/watch?v=gtUPPO8Re98

I ran into this issue as well. My fix was to create a child schema. See below for an example for your models.
---- Person model
const mongoose = require('mongoose');
const SingleFriend = require('./SingleFriend');
const Schema = mongoose.Schema;
const productSchema = new Schema({
friends : [SingleFriend.schema]
});
module.exports = mongoose.model('Person', personSchema);
***Important: SingleFriend.schema -> make sure to use lowercase for schema
--- Child schema
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const SingleFriendSchema = new Schema({
Name: String
});
module.exports = mongoose.model('SingleFriend', SingleFriendSchema);

Finding users who has signed between given dates using Mongoose

I have user model like this
const guestSchema = mongoose.Schema({
facebook: {
id: String,
token: String,
email: String,
name: String,
phone: String,
dates: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "loginDate"
}
]
}
});
and loginDate model
const loginDateSchema = mongoose.Schema({
loginDate: Date
});
Every time user signs in current Date is added.
How can I find users who have signed in between given date?
I did below but I am getting empty result
Guest.find({ "facebook.id": { $exists: true } })
.populate("facebook.dates")
.find({ "facebook.dates": { $gte: startDate,$lte: endDate } })
.exec((err, foundUsers) => {
res.render("./admin/send", {
facebookUsers: foundUsers
});
});
Sample JSON
{
"_id" : ObjectId("5a1a838f58eb1a50c408de84"),
"facebook" : {
"email" : "sample#yahoo.com",
"name" : "Sample user",
"id" : "12345",
"dates" : [
ObjectId("5a1a838f58eb1a50c408de85"),
ObjectId("5a1a839258eb1a50c408de86"),
ObjectId("5a1a839358eb1a50c408de87"),
ObjectId("5a1a839758eb1a50c408de88"),
ObjectId("5a1aa17058eb1a50c408de8b")
]
},
"__v" : NumberInt(5)
}
LoginDate
{
"_id" : ObjectId("5a1a839358eb1a50c408de87"),
"loginDate" : ISODate("2017-11-26T09:04:19.107+0000"),
"__v" : NumberInt(0)
}

I think the issue is with your date which you are passing into find function on line
.find({ "facebook.dates": { $gte: startDate,$lte: endDate } })
You need to pass a date object and not a date string.
Here is my solution which is working fine for me
Facebook model
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
mongoose.Promise = global.Promise;
var facebookSchema = new Schema({
id: String,
token: String,
email: String,
name: String,
phone: String,
logindate: Date
},
{
versionKey: false
}
);
module.exports = mongoose.model('Facebook', facebookSchema);
Here is data
[
{
"_id":"5a2949d40591a2192c8fad6b",
"logindate":"2016-10-10T06:28:37.146Z",
"phone":"03006351611",
"name":"mainuhassan",
"email":"mainuhassan#gmail.com",
"token":"MxuXmblL56aqt17aHh1rqcyeHc0E4CwQ",
"id":"100"
},
{
"_id":"5a294cd26c3e661514f3699e",
"logindate":"2015-10-10T06:28:37.146Z",
"phone":"03006351611",
"name":"mainuhassan1",
"email":"mainuhassan1#gmail.com",
"token":"MxuXmblL56aqt17aHh1rqcyeHc0E4CwQ",
"id":"100"
},
{
"_id":"5a294cfe75e2ba2778e9f249",
"logindate":"2017-10-10T06:28:37.146Z",
"phone":"03006351612",
"name":"mainuhassan2",
"email":"mainuhassan2#gmail.com",
"token":"MxuXmblL56aqt17aHh1rqcyeHc0E4CwQ",
"id":"100"
}
]
And here is my code for getting data between dates
Facebook.find({ logindate: { "$gte": new Date("2016-10-10T06:28:37.146Z"), "$lte": new Date("2017-10-10T06:28:37.146Z") } })
.exec(function(error, facebook){
if (!error) {
res.send(facebook);
}
});