MongoDb - bounded array with empty values shows unbounded - javascript

In my novice skill to Mongodb and Mongoose, I seem to be failing miserably at this fundamental task.
I have a bounded array of 10 elements. A user can only have 10 pets, so I figured to make it bounded with set fields and empty values was the best way.
The pets array values are blank at the time of creation, because the user can add pets as they go along. When I look in mongo console, the pets array is unbounded with no fields. I also can't add values to the array.
Mongoose Schema:
var userSchema = new Schema({
firstName: { type: String, required: true },
lastName: { type: String, required: true },
username: { type: String, required: true, unique: true },
location: String,
created_at: Date,
pets: [
{ "pet0": {} },
{ "pet1": {} },
{ "pet2": {} },
{ "pet3": {} },
{ "pet4": {} },
{ "pet5": {} },
{ "pet6": {} },
{ "pet7": {} },
{ "pet8": {} },
{ "pet9": {} }
]
});
mongodb:
{ "_id" : ObjectId("56a3e324bdebcf801c1ca224"), "firstName" : "bob", "lastName" : "smith", "username" : "bob123", "pets" : [ ], "__v" : 0 }
When modifying the array:
UserModel.findOne({ firstName: "bob" }, 'pets', function(err, user) {
user.pets[0] = { "name": "felix", "type": "cat" }
user.save(function(err) { console.log(err); console.log('saved')});
});
output:
Mongoose: users.findOne({ firstName: 'bob' }) { fields: { pets: 1 } }
null
/home/one/github/foo/node_modules/mongoose/lib/schema/documentarray.js:100
doc.validate({ __noPromise: true }, function(err) {
^
TypeError: undefined is not a function
at /home/one/github/foo/node_modules/mongoose/lib/schema/documentarray.js:100:11
at DocumentArray.SchemaType.doValidate (/home/one/github/foo/node_modules/mongoose/lib/schematype.js:654:22)
at DocumentArray.doValidate (/home/one/github/foo/node_modules/mongoose/lib/schema/documentarray.js:78:35)
at /home/one/github/foo/node_modules/mongoose/lib/document.js:1156:9
at process._tickCallback (node.js:355:11)

MongoDB allows you to limit the number of elements in an array. This feature has also been implemented in Mongoose as part of an .update query. The steps for adding an element to an array and limiting its size are as follows:
Push the element(s) into the array.
Slice the array.
This snippet of code explains how to do this using Mongoose:
UserModel.findOne({ firstName: "bob" }, function(err, user) {
UserModel.update(user, {
$push: {
pets: {
$each: [{ name: "felix", type: "cat" }],
$slice: -10
}
}
}, function(err, numAffected) {
if (err) console.log(err);
console.log('updated');
});
});

Related

How can i iterate mongoose returned documents array in loop using mongoose?

I have a node.js(express based) server in which i have a function which returns all users. Here is the function.
export async function findAllUser() {
let users = await User.find({}).exec()
return users
}
In my node.js applicaiton i have two models(schema) of Users and Referrals like this .
var User = mongoose.model(
"users",
new Schema({
first_name: String,
last_name: String,
name: String,
email: String,
password: String,
roleId: { type: Number, default: 0 },
country: String,
token: String,
createdAt: String,
updatedAt: String,
tempToken: String,
verificationCode: String,
fbUserId: String,
isFbUser: { type: Boolean, default: false },
isActive: { type: Boolean, default: true },
isEmailVerified: { type: Boolean, default: false },
rememberme: Boolean,
}, {
toJSON: { virtuals: true },
toObject: { virtuals: true }
})
);
User.virtual("referrals", {
ref: "referralLinks",
foreignField: "userId",
localField: "_id"
});
export var ReferralLink = mongoose.model(
"referralLinks",
new Schema({
referral_link: String,
referral_code: String,
isLink: Number,
offer_name: String,
offer_desc: String,
user_email: String,
companyId: { type: Schema.Types.ObjectId, ref: 'companies' },
addedByAdmin: { type: Boolean, default: true },
number_of_clicks: Number,
referral_country: String,
link_status: String,
categoryId: { type: Schema.Types.ObjectId, ref: 'categories' },
number_of_clicks: { type: Number, default: 0 },
createdAt: String,
updatedAt: String,
userId: { type: Schema.Types.ObjectId, ref: 'users' }
})
);
I have my separate api.route.js file in which i have get all users route like this
router.get("/", log, getAllUsers);
And i my api.controller.js file i have getAllUsers like this
export async function getAllUsers(req, res) {
try {
let Users = await findAllUser()
if (Users) {
generateResponse(true, "All Users fetched", Users, res)
} else {
generateResponse(false, "No Users found", null, res)
}
} catch (err) {
generateResponse(false, 'Error occured, 404 not found!', err, res)
}
}
And in my api.handler.js file i have findAllUser function like this
export async function findAllUser() {
let users = await User.find({}).populate("referrals").exec()
return users
}
Single user can have more than one Referrals. But unfortunately i don't have 'Referrals' reference _id in Users document. Now, i want to get all users with their respective Referrals
I am getting all users correctly but for each user i also want to fetch all their respective referrals. So for that i definitely can't use for or forEach loop because of async nature of mongoose find. So what should i use instead of for or forEach loop?
My desired results
results = [
{
first_name : "Fahad",
last_name : "subzwari",
email : "fahadsubzwari#gmail.com",
password : "***",
referrals : [
{
//referral object 1
},
{
//referral object 2 ...
}
]
},
{
first_name : "Alex",
last_name : "Hales",
email : "alex#gmail.com",
password : "***",
referrals : [
{
//referral object 1
},
{
//referral object 2 ...
},
{
//referral object 3 ...
}
]
},
]
To be able to access referrals from user you need to use virtual populate.
So your userSchema must be like this:
const userSchema = new Schema(
{
first_name: String,
last_name: String,
name: String,
email: String,
password: String,
roleId: { type: Number, default: 0 },
country: String,
token: String,
createdAt: String,
updatedAt: String,
tempToken: String,
verificationCode: String,
fbUserId: String,
isFbUser: { type: Boolean, default: false },
isActive: { type: Boolean, default: true },
isEmailVerified: { type: Boolean, default: false },
rememberme: Boolean
},
{
toJSON: { virtuals: true },
toObject: { virtuals: true }
}
);
// Virtual populate
userSchema.virtual("referrals", {
ref: "referralLinks",
foreignField: "userId",
localField: "_id"
});
var User = mongoose.model("users", userSchema);
And now you can use this route to access referrals from users:
router.get("/", async (req, res) => {
const result = await User.find({}).populate("referrals");
res.send(result);
});
The result will be like this: ( I excluded some fields for simplicity)
[
{
"_id": "5dd6819201419f5930d02334",
"name": "User 1",
"email": "user1#gmail.com",
"password": "123123",
"__v": 0,
"referrals": [
{
"_id": "5dd6829831b95a6b2cd58fca",
"referral_link": "referral_link 1",
"userId": "5dd6819201419f5930d02334",
"__v": 0
},
{
"_id": "5dd682a031b95a6b2cd58fcb",
"referral_link": "referral_link 2",
"userId": "5dd6819201419f5930d02334",
"__v": 0
}
],
"id": "5dd6819201419f5930d02334"
},
{
"_id": "5dd681a101419f5930d02335",
"name": "User 2",
"email": "user2#gmail.com",
"password": "123123",
"__v": 0,
"referrals": [
{
"_id": "5dd682a731b95a6b2cd58fcc",
"referral_link": "referral_link 3",
"userId": "5dd681a101419f5930d02335",
"__v": 0
}
],
"id": "5dd681a101419f5930d02335"
}
]
UPDATE:
Here is the steps for your project setup:
api.handler.js:
exports.findAllUser = async function() {
console.log("api handler inside");
let users = await User.find({})
.populate("referrals")
.exec();
console.log("in handler: ", users);
return users;
};
api.controller.js:
const handler = require("./api.handler");
exports.getAllUsers = async function(req, res) {
console.log("userController.getAllUsers");
try {
let Users = await handler.findAllUser();
if (Users) {
return res.send(Users);
generateResponse(true, "All Users fetched", Users, res);
} else {
generateResponse(false, "No Users found", null, res);
}
} catch (err) {
generateResponse(false, "Error occured, 404 not found!", err, res);
}
};
api.route.js
const apiController = require("../controllers/api.controller");
router.get("/", log, apiController.getAllUsers);
You say "i don't have 'Referrals' reference _id in Users" so I assume you have a reference to the user in the Referrals schema?
Otherwise, with no way to link them you are lost at sea I'm afraid... :-(
If you do then you would do it in a separate query:
const userIds = users.map(user => user._id);
const referrals = await Referrals.find({ userId: { $in: userIds } })
The $in operator will grab any field where the user id is included in the array.
EDIT: In response to your update - yes the above should work fine. Then you can do what you want with them e.g. map the referrals to the user objects, or use them individually etc. etc.
EDIT2: Yep this is the way. At this point you have an array of users and an array of referrals so you just need to put them together.
users.map(user => ({
// add props from user obj
...user,
// add all referrals that with matching userId
referrals: referrals.filter(referral => referral.userId === user._id)
}))
Remember that as you are dealing with asynchronous calls and promises so you will either need to use the async/await keywords, or parse the results in the promise callback.

Mongoose/Mongodb: Index Already Exists With Different Options

I am using Mongoose 5.1.7 and attempting to create a compound index across multiple text indexes in my defined schema. Here is my schema definition:
const mongoose = require('mongoose');
const alumniSchema = mongoose.Schema({
firstName: {
type: [String],
required: true
},
lastName: {
type: [String],
required: true
},
classYear: {
type: Number,
required: true
},
photoURL: {
type: String,
},
education: [
{
school: {
type: String,
required: true
},
gradYear: {
type: Number,
required: true
},
degreeType: String,
degreeSubject: String,
}
],
jobs: [
{
employer: {
type: String,
required: true
},
position: String,
startDate: Date,
endDate: Date,
isCurrent: Boolean
}
],
contactInfo: {
phoneNumber: {
type: String,
},
email: {
type: String,
}
},
})
alumniSchema.index({ firstName: 'text', lastName : 'text', email: 'text' });
module.exports = mongoose.model('Alumni', alumniSchema);
When I boot up the server, I receive the following error:
MongoError: Index: { v: 2, key: { _fts: "text", _ftsx: 1 }, name: "firstName_text_lastName_text_email_text", ns: "5b3be578c0c6e317f7c1bc2b_test.alumnis", background: true, weights: { email: 1, firstName: 1, lastName: 1 }, default_language: "english", language_override: "language", textIndexVersion: 3 } already exists with different options: { v: 2, key: { _fts: "text", _ftsx: 1 }, name: "firstName_text_lastName_text_classYear_text_education.school_text", background: true, weights: { classYear: 1, education.school: 1, firstName: 1, lastName: 1 }, default_language: "english", language_override: "language", ns: "5b3be578c0c6e317f7c1bc2b_test.alumnis", textIndexVersion: 3 }
I have been messing around with this for a while and evidently previously created an index. When I use the mongo shell to check the indexes that I currently have set up, however, I cannot find the index "firstName_text_lastName_text_classYear_text_education.school_text" referenced by the error message:
> db
test
> db.collection.getIndexes()
[ ]
I am at an impasse--I'm not sure if I've incorrectly created the index, or if I am supposed to drop the index (it doesn't look like Mongoose natively supports a dropIndex() function).
Has anyone else dealt with this issue? Thanks!
Looks like Mongoose dynamically creates the index at runtime. The trick for me was adding:
var Alumni = mongoose.model('Alumni', alumniSchema);
Alumni.collection.dropIndex('firstName_text_lastName_text_classYear_text_education.school_text', function(err, result) {
if (err) {
console.log('Error dropping index!', err);
}
});
and then restarting the server.
THEN I was able to change the index to whatever I wanted. Note that I still needed to add the above code segment and restart the server every time I wanted to update the index.

Determine if value exists in user's embedded document array

I know the User's ID, and I want to know if they have a value in their groceryList that matches "name" = "foo". Here is my current query, but it is returning result even though the name doesn't exist, I'm assuming since one of the values exists. How do I make it only return result if both values are true?
User.findOne( {"_id": req.user._id},{"groceryList": {"$elemMatch": {"name": ingredients.name[i]}}}, function(err, result) {
if(err) {
console.log(err);
}
else if(result) {
console.log(result);
}
})
User Schema:
var groceryListSchema = mongoose.Schema({
quantity: { type: Number, required: true },
measurement: { type: String, required: true },
name: { type: String, required: true }
});
var userSchema = new mongoose.Schema({
username: String,
password: String,
recipes: [
{
type: mongoose.Schema.Types.ObjectId,
ref: 'Recipe'
}
],
groceryList: {
type: [ groceryListSchema ]
}
});
the second argument should be a part of your query.
User.findOne({"_id": req.user._id, "groceryList": {"$elemMatch": {"name": ingredients.name[i]}}})
and as pointed out above it would be simpler to write:
Users.findOne({"_id": req.user._id, "groceryList.name": ingredients.name[i] })

How to add to arrays in mongoose using node.js

I have this type of mongoose schema shown below:
const brandSchema = mongoose.Schema({
brandname: {
type: [],
require: true,
},
frequency: {
type: [
{brand1 : []},
{brand2 : []}
],
},
date: {
type: [],
}
})
I want to be able to add two brandname to it at the to, then id find the brand name then keep appending values to the array later. Is there a way I can do this?
You can use $push operator in findOneAndUpdate method. Example:
Model.findOneAndUpdate(
{ "_id": model._id, "projects._id": id },
{$push: {
[`projects.$.path.${version}`]: {path: `${sha256}.${ext}`}
}},
(err, doc) => {
if (err) {
res.status(500).json({status: 'error'});
}
}
);

Find documents that contain certain field for sub-object MongoDb and Node.js

I have a collection with the following format:
[
{
firstname: 'Joe',
lastname: 'Blow',
emails: [
{
email: 'test#example.com',
valid: false
},
{
email: 'test2#example.com',
valid: false
}
],
password: 'abc123',
_id: 57017e173915101e0ad5d94a
},
{
firstname: 'Johnny',
lastname: 'Doe',
emails: [
{
email: 'test3#example.com',
valid: false
}
],
password: 'abc123',
_id: 57017e173915101e0ad5d87b
},
]
I am trying to find a user based on the emails.email field. Here is what I have so far:
db.collection('users').aggregate([
{$unwind: "$emails"},
{$group: {_id: "$_id",user_emails: { $push: "$emails.email" } } },
{$match: {'user_emails': { $in: ['test#example.com'] } } }
],
(error, result) => {
console.log(error);
console.log(result);
}
);
When I run this command in the mongo shell it seems to work; however when I run it in Node.js it prints null for the error and [] for the result.
What am I doing wrong? I am pretty new to MongoDB and just can't seem to figure this out.
Why do you want to unwind the entire emails? That will be a very expensive operation when your collection grows with tons of records.
The below query will return the user with the email test2#example.com. I think thats what you are looking for right?
db.email.find({emails :{$elemMatch:{email:"test2#example.com"}}})
I have re-written your code with slight changes.
var col = db.collection('collection');
if (col) {
col.aggregate([
{$unwind: "$emails"},
{$group: {_id: "$_id",user_emails: { $push: "$emails.email" } } },
{$match: {'user_emails': { $in: ['test#example.com'] } } }
], function(e, r){
if(e){
console.log(error);
}
console.log(r);
db.close();
});
}
It should work, provided you have establish connection and other requirements successfully. Provided your sample documents, it will emit:
[
{
_id: '57017e173915101e0ad5d94a',
user_emails: [
'test#example.com',
'test2#example.com'
]
}
]

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