This is maybe more a case of looking for advice. However, I will supply sample code as an example of what I want to achieve. I am trying to build my first back end system and I keep running into problems with the design.
My MongoDB database consists of 4 major parts - Profiles, Teams, Drafts and Users. The profile (being the main data which sources everything using IDs) schema has properties to hold arrays with the Teams and Drafts IDs. The idea is that when the profile is served it will populate all those properties with the relevant data by using the IDs.
Example of the Profile schema using Mongoose:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var UserProfileSchema = new Schema({
Name : String,
Email : String,
Admin : Boolean,
Status : Number,
UserID : String,
PrivateProfile: Boolean,
Drafts: [String], //This array holds the draft IDs
Teams:[String] //Holds the team profiles IDs
});
module.exports = mongoose.model('UserProfile', UserProfileSchema);
Example of Team Profile Schema using Mongoose:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var TeamProfileSchema = new Schema({
Name : String,
CaptainID : String,
CaptainName : String,
Members : [String], //Array of user IDs
DateCreated : Boolean,
Reputation : Number
});
module.exports = mongoose.model('TeamProfile', TeamProfileSchema);
Example of a route to find all the Team Profiles the user is the Captain of and fetch all the members associated with that team:
router.route('/teams/captain/:user_id')
.get(function (req, res) {
TeamProfile.find({
CaptainID : req.params.user_id
}, function (err, teams) {
if (err)
res.send(err);
for (var x in teams) {
var membersArray = [];
for (var i in teams[x].Members) {
var ID = teams[x].Members[i];
UserProfile.find({
UserID : ID
}, function (err, profile) {
if (err)
res.send(err);
membersArray.push(profile);
});
}
teams[x].Members = membersArray;
console.log(teams[x].Members);
}
res.json(teams);
});
})
I understand that the route will not work, but how do I pull this off? I used a more vanilla approach only for the purpose to explain what I want to achieve. Any help would be highly appreciated.
I advise you to use combination of denormalization and normalization.
because MongoDB is not a relational database.
denormalization is much faster then normalization. You don't need to use relationship anymore.
You can read this article hope may helpfull to you.
Cheers
Related
Given a situation where you have a User Scheme that you use to create a base model called User. And then for user roles, you use mongoose discriminators to create inherited models called Admin, Employee and Client. Is there a way to programmatically determine how many discriminations/inheritances/roles of the User model are available, as well as the available names?
My question in terms of code:
File: models/user.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var options = {discriminatorKey: 'role'};
var userSchema = mongoose.Schema({
name: String,
email: String,
password: String,
},options);
var User = mongoose.model('User', userSchema);
var Client = User.discriminator("Client", mongoose.Schema({
Address : String,
Tax_identification : String,
Phone_number : String,
Internal_Remarks : String,
CRM_status : String,
Recent_contact : String,
}));
var Employee = User.discriminator("Employee",mongoose.Schema({
Staff_Id: String,
}));
module.exports = {User: User, Client: Client, Employee: Employee };
File: controllers/usersController.js
var User = require('../models/user.js').User;
module.exports = {
registerRoutes: function(app){
app.get('user/create',this.userCreateCallback)
},
userCreateCallback: function(req,res){
//Get Available User Roles - The function below doesn't exist,
//Just what I hypothetically want to achieve:
User.geAvailableDiscriminators(function(err,roles){
res.render('user/create',{roles:roles})
});
}
};
I hope I managed to express what I want to do. Alternative approaches are also welcome.
Since v4.11.13, mongoose model has model.discriminators which is an array of models, keyed on the name of the discriminator model.
In your case if you do console.log(User.discriminators) you will get:
{
Client: {
....
},
Employee: {
}
}
As far as I can see, this is not documented anywhere.
Line 158 in lib.helpers.model.discriminators.js is where this is created.
I think you want to fetch the names and values of all the discriminators as for the names you can simply use
User.discriminators
but for finding values you can use this
return Promise.all(Object.keys(discriminators).map(i =>
discriminators[i].find({ userId: this._id }))
).then(promiseResults =>
promiseResults.reduce((arr, el) => arr.concat(el), [])
);
you need to put userId under each discriminators for that.
I've recently started using Mongoose with Express.js in a Node.js application and I have a question about a proper way to design my schemas.
I have several schemas that have some relationships, i.e. Location schema has an array of Objects (it's not a JS object in this context), and Object schema has its Location property. I've learned that relationships in Mongoose are resolved using population, but when I implemented this approach I noticed that I have to type a lot of duplicate code, i.e. whenever I want to create a new Object I have to also update the Location's array of Objects and then assign the Location to the Object's property. Wouldn't it be more trivial to just manually assemble all the Objects that has a locationId property equal to the Location that I want to get from the database in a separate query?
I have also considered just storing Objects in an array in a Location document (as subdocuments) but I decided that I want to be able to work with Objects (create, remove, update) separately from Locations (without querying a Location) so this approach doesn't fit my needs I guess. But then population has its drawbacks too in my case, so I guess it's really the best to just go with manually collecting Objects of a specific Location in a separate query by that Location's id.
I would like to hear an opinion of some professional or advanced user of this technology on designing Mongoose schemas so that I and others don't get into trouble later maintaining and scaling our applications.
Here are my current schemas in question:
var locationSchema = new mongoose.Schema({
title: String,
objects: [{ type: String, ref: 'object' }]
});
var objectSchema = new mongoose.Schema({
title: String,
location: { type: String, ref: 'location' }
});
Checkout this example
db/schemas.js:
const Schema = mongoose.Schema;
const ObjectSchema = {
title: Schema.Types.String
}
const LocationSchema = new Schema({
title: Schema.Types.String,
objects: [{type: Schema.Types.ObjectId, ref: 'Object'}]
})
module.exports = {
Object: ObjectSchema,
Location: LocationSchema
};
db/model.js:
const
mongoose = require('mongoose'),
schemas = require('./schemas');
module.exports = model => mongoose.model(model, schemas[model+'Schema']);
usage:
const
model = require('./db/model'),
LocationModel = model('Location');
LocationModel
.findOne({_id: 'some id here'})
.populate('objects')
.exec((err, LocationInstance) => {
console.log(LocationInstance.title, ' objects:', LocationInstance.objects);
});
when You create an object and want to relate to location:
const
model = require('./db/model'),
ObjectModel = model('Object'),
LocationModel = model('Location');
let
ObjectInstance = new ObjectModel({title: 'Something'});
ObjectInstance.save((err, result) => {
LocationModel
.findByIdAndUpdate(
'some id here',
{$push: {objects: ObjectInstance._id}},
(err) => {
console.log('Object:', ObjectInstance.title, ' added to location');
});
});
updating object data:
const
model = require('./db/model'),
ObjectModel = model('Object');
let id = 'id of object';
ObjectModel
.findByIdAndUpdate(
id,
{title: 'Something #2'},
(err) => {
console.log('Object title updated');
});
finding location by object:
const
model = require('./db/model'),
LocationModel = model('Object');
let id = 'id of object';
LocationModel
.findOne({objects: id})
.populate('objects')
.exec((err, LocationInstance) => {
console.log('Location objects:', LocationInstance.objects);
});
nothing special findOne({objects: id}) will search inside location documents that has relation by id in objects array
any other question welcome (:
Allora, I'm using mongoose for the first time and I decided to create 2 schemes: the first one represents a user and the second one represents his enquires. Users have an array of enquires like:
var userSchema = new mongoose.Schema({
name: String,
enquires: { type : [Enquire.schema] , "default" : [] },
});
var enquireSchema = new mongoose.Schema({
status: {type: String, 'default': 'pending'},
enquire: String,
});
I see that if I search for an enquire and update its status, it doesn't update the same enquire on the user's array, meaning that they are different object. I don't want to save an array of IDs as it will be the same as a relational database, so I see only 1 solution which is forgetting about the enquire scheme and use only the User scheme. Is it the way mongoose works? For every relationship do I have to insert everything like nested object?
I think you should use references to achieve what you want to achieve.
For more information on mongoose references and populate see Mongoose Populate documentation.
Try this, It may help you.
User Schema :
var userSchema = new mongoose.Schema({
name: String,
enquires: [{ type : mongoose.Schema.Types.ObjectId , ref : 'Enquiry' }]//array of enquiries
});
var User = mongoose.model('User',userSchema );
module.exports = User;
Enquiry Schema :
var enquireSchema = new mongoose.Schema({
status: {type: String, 'default': 'pending'},
enquire: String,
});
var Enquiry = mongoose.model('Enquiry',enquireSchema );
module.exports = Enquiry ;
Working :
create a new Enquiry.
Push it's ID(_id) into user's enquires array.
var enquiry = new Enquiry();
enquiry.enquire = "Dummy enquiry";//set the enquiry
enquiry.save(function(err,result){
if(!err){
//push 'result._id' into users enquires array
}
});
whenever you update an enquiry, it will be automatically updated in
user's document.
use populate to retrieve user's enquiries.
You can embed sub documents (entity) which has id and is like a document or embed native array like a normal property.
And I think the correct definition for yours is :
var enquireSchema = new mongoose.Schema({
status: {type: String, 'default': 'pending'},
enquire: String,
});
var userSchema = new mongoose.Schema({
name: String,
enquires: { type : [enquireSchema] , "default" : [] },
});
If you use refs in embedded link then there are two separate collections and be like relational db's.
I'm working on a query that reads from 2 different obj referentes inside my mongo database. I will use a simple example of what im looking for.
I have 3 schemas:
User = new Schema({
places:[{type: Schema.Types.ObjectId, ref:'Place'}],
shouts:[{type: Schema.Types.ObjectId, ref:'Shout'}]
});
Place = new Schema({
name:String,
description:String,
});
Shout = new Schema({
content:String,
});
My biggest question is if mongoose or mongodb has access to objectId references when executing the aggregate method. Allow me to elaborate.
module.exports.askForShoutInPlace = function(req, res){
var pname = new RegExp(req.params.pname, 'i');
User.aggregate(
[
{'$match':{ 'places':{
'$elemMatch':{'name':pname}
}
},
{'$project':{ shout:'$shouts'} },
{'$unwind':'$shouts'},
{'$group':{_id:'$shouts'}}
]).exec(function(err, results){
res.send(results);
});
}
That usually works fine, however I'm getting an empty array once the $match operator is called, im guessing it has to do with the object references returning undefined subobjects. is there any work around this? or does this mean I have to take another route to employ populating?
thanks for all the help in advance
there's no way to access object Referenced data during the aggregate Process, the work around I employed for my project was to add a reference to the owner in the schemas in question.
User = new Schema({
places:[{type: Schema.Types.ObjectId, ref:'Place'}],
shouts:[{type: Schema.Types.ObjectId, ref:'Shout'}]
});
Place = new Schema({
owner:{type: Schema.Types.ObjectId, ref:'Place'},
name:String,
description:String,
});
Shout = new Schema({
owner:{type: Schema.Types.ObjectId, ref:'Place'},
content:String,
});
And then employed to Aggregate directly on the subdocument to obtain the unique users who own the instances of of place, this way I can obtain a shout result matching a query and a place.
Example:
module.exports.askForShoutInPlace = function(req, res){
var pname = new RegExp(req.params.pname, 'i');
var stringQ = new RegExp(req.paramos.qcontent, 'i');
Place.aggregate(
[
//find Places that match criteria
{'$match':{'name':pname}},
//select owner id object to result
{'$project':{ owner:'$owner'}},
//group those results to single array with unique ids of users
{'$group':{_id:'$owner'}}
]).exec(function(err, results){
//find user shouts that match string and belong to owners know to be owners of a place
Shout.find({'content':stringQ}).where({'owner':{'$in':results}}).exec(function(err, shouts){
res.send(shouts);
});
});
}
this is just the way I found to work around my particular needs, I hope it might help somebody.
I want to give users the ability to create collections in my Node app. I have really only seen example of hard coding in collections with mongoose. Anyone know if its possible to create collections dynamically with mongoose? If so an example would be very helpful.
Basically I want to be able to store data for different 'events' in different collections.
I.E.
Events:
event1,
event2,
...
eventN
Users can create there own custom event and store data in that collection. In the end each event might have hundreds/thousands of rows. I would like to give users the ability to perform CRUD operations on their events. Rather than store in one big collection I would like to store each events data in a different collection.
I don't really have an example of what I have tried as I have only created 'hard coded' collections with mongoose. I am not even sure I can create a new collection in mongoose that is dynamic based on a user request.
var mongoose = require('mongoose');
mongoose.connect('localhost', 'events');
var schema = mongoose.Schema({ name: 'string' });
var Event1 = mongoose.model('Event1', schema);
var event1= new Event1({ name: 'something' });
event1.save(function (err) {
if (err) // ...
console.log('meow');
});
Above works great if I hard code 'Event1' as a collection. Not sure I create a dynamic collection.
var mongoose = require('mongoose');
mongoose.connect('localhost', 'events');
...
var userDefinedEvent = //get this from a client side request
...
var schema = mongoose.Schema({ name: 'string' });
var userDefinedEvent = mongoose.model(userDefinedEvent, schema);
Can you do that?
I believe that this is a terrible idea to implement, but a question deserves an answer. You need to define a schema with a dynamic name that allows information of 'Any' type in it. A function to do this may be a little similar to this function:
var establishedModels = {};
function createModelForName(name) {
if (!(name in establishedModels)) {
var Any = new Schema({ any: Schema.Types.Mixed });
establishedModels[name] = mongoose.model(name, Any);
}
return establishedModels[name];
}
Now you can create models that allow information without any kind of restriction, including the name. I'm going to assume an object defined like this, {name: 'hello', content: {x: 1}}, which is provided by the 'user'. To save this, I can run the following code:
var stuff = {name: 'hello', content: {x: 1}}; // Define info.
var Model = createModelForName(name); // Create the model.
var model = Model(stuff.content); // Create a model instance.
model.save(function (err) { // Save
if (err) {
console.log(err);
}
});
Queries are very similar, fetch the model and then do a query:
var stuff = {name: 'hello', query: {x: {'$gt': 0}}}; // Define info.
var Model = createModelForName(name); // Create the model.
model.find(stuff.query, function (err, entries) {
// Do something with the matched entries.
});
You will have to implement code to protect your queries. You don't want the user to blow up your db.
From mongo docs here: data modeling
In certain situations, you might choose to store information in
several collections rather than in a single collection.
Consider a sample collection logs that stores log documents for
various environment and applications. The logs collection contains
documents of the following form:
{ log: "dev", ts: ..., info: ... } { log: "debug", ts: ..., info: ...}
If the total number of documents is low you may group documents into
collection by type. For logs, consider maintaining distinct log
collections, such as logs.dev and logs.debug. The logs.dev collection
would contain only the documents related to the dev environment.
Generally, having large number of collections has no significant
performance penalty and results in very good performance. Distinct
collections are very important for high-throughput batch processing.
Say I have 20 different events. Each event has 1 million entries... As such if this is all in one collection I will have to filter the collection by event for every CRUD op.
I would suggest you keep all events in the same collection, especially if event names depend on client code and are thus subject to change. Instead, index the name and user reference.
mongoose.Schema({
name: { type: String, index: true },
user: { type: mongoose.Schema.Types.ObjectId, ref: 'User', index: true }
});
Furthermore I think you came at the problem a bit backwards (but I might be mistaken). Are you finding events within the context of a user, or finding users within the context of an event name? I have a feeling it's the former, and you should be partitioning on user reference, not the event name in the first place.
If you do not need to find all events for a user and just need to deal with user and event name together you could go with a compound index:
schema.index({ user: 1, name: 1 });
If you are dealing with millions of documents, make sure to turn off auto index:
schema.set('autoIndex', false);
This post has interesting stuff about naming collections and using a specific schema as well:
How to access a preexisting collection with Mongoose?
You could try the following:
var createDB = function(name) {
var connection = mongoose.createConnection(
'mongodb://localhost:27017/' + name);
connection.on('open', function() {
connection.db.collectionNames(function(error) {
if (error) {
return console.log("error", error)
}
});
});
connection.on('error', function(error) {
return console.log("error", error)
});
}
It is important that you get the collections names with connection.db.collectionNames, otherwise the Database won't be created.
This method works best for me , This example creates dynamic collection for each users , each collection will hold only corresponding users information (login details), first declare the function dynamicModel in separate file : example model.js
/* model.js */
'use strict';
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
function dynamicModel(suffix) {
var addressSchema = new Schema(
{
"name" : {type: String, default: '',trim: true},
"login_time" : {type: Date},
"location" : {type: String, default: '',trim: true},
}
);
return mongoose.model('user_' + suffix, addressSchema);
}
module.exports = dynamicModel;
In controller File example user.js,first function to create dynamic collection and second function to save data to a particular collection
/* user.js */
var mongoose = require('mongoose'),
function CreateModel(user_name){//function to create collection , user_name argument contains collection name
var Model = require(path.resolve('./model.js'))(user_name);
}
function save_user_info(user_name,data){//function to save user info , data argument contains user info
var UserModel = mongoose.model(user_name) ;
var usermodel = UserModel(data);
usermodel.save(function (err) {
if (err) {
console.log(err);
} else {
console.log("\nSaved");
}
});
}
yes we can do that .I have tried it and its working.
REFERENCE CODE:
app.post("/",function(req,res){
var Cat=req.body.catg;
const link= req.body.link;
const rating=req.body.rating;
Cat=mongoose.model(Cat,schema);
const item=new Cat({
name:link,
age:rating
});
item.save();
res.render("\index");
});
I tried Magesh varan Reference Code ,
and this code works for me
router.post("/auto-create-collection", (req, res) => {
var reqData = req.body; // {"username":"123","password":"321","collectionName":"user_data"}
let userName = reqData.username;
let passWord = reqData.password;
let collectionName = reqData.collectionName;
// create schema
var mySchema = new mongoose.Schema({
userName: String,
passWord: String,
});
// create model
var myModel = mongoose.model(collectionName, mySchema);
const storeData = new myModel({
userName: userName,
passWord: passWord,
});
storeData.save();
res.json(storeData);
});
Create a dynamic.model.ts access from some where to achieve this feature.
import mongoose, { Schema } from "mongoose";
export default function dynamicModelName(collectionName: any) {
var dynamicSchema = new Schema({ any: Schema.Types.Mixed }, { strict: false });
return mongoose.model(collectionName, dynamicSchema);
}
Create dynamic model
import dynamicModelName from "../models/dynamic.model"
var stuff = { name: 'hello', content: { x: 1 } };
var Model = await dynamicModelName('test2')
let response = await new Model(stuff).save();
return res.send(response);
Get the value from the dynamic model
var Model = dynamicModelName('test2');
let response = await Model.find();
return res.send(response);