I have the legacy backend. This backend use mongoose. There is collection "Users". This collection has "email" field.
I was faced with the bug - email is case sensitive. I want to save all new emails in lower case. For this I've modified "Users" schema with this:
email: {
type: String,
lowercase: true
}
But also backend has a lot of places with things like:
user.find({email: some_case_unnormalized_email})
or this:
user.findOne({email: some_case_unnormalized_email})
I don't want to modify that places to:
user.find({email: some_case_unnormalized_email.toLowerCase()})
Instead, I want to create some middleware for "Users" schema like:
UsersSchema.middleware('any_query', queryObject => {
if (queryObject.email) {
queryObject.email = queryObject.email.toLowerCase();
}
});
How to do that?
Use pre save hook to modify any property
UserSchema.pre('find', function(next){
var query = this;
// console.log(JSON.stringify(query, null, 2));
// update your query here
next();
})
UserSchema.pre('findOne', function(next){
var query = this;
// console.log(JSON.stringify(query, null, 2));
// update your query here
next();
})
Related
Hello I have less idea in express route as I am new in backend with mongodb.
In the route below I am verifying email by resetting a schema value to true. Now I want to copy the new schema details to another existing collection. How can I do that ?
router.get('/:adminId/verifyAdmin',function(req,res){
console.log('request recieved');
Admin.findOne( {_id: req.params.adminId })
.exec()
.then(admin => {
const Thing = mongoose.model(admin.companyName);
const emailTokenn = req.query.id;
//console.log(emailTokenn);
Thing.updateOne( { emailResetTokenn: emailTokenn },{ $set: { verified: true }},(err) =>{
if(!err){
return res.redirect('https://localhost:3000/fw18/index.html');
}
else{
throw err;
}
});
});
});
Here I want to pass/copy/save Thingcollection details to existing collection name users in my db.
EDIT:- Tried this but getting error export :- const User = mongoose.model('User');
Thing.updateOne( { emailResetTokenn: emailTokenn },{ $set: { verified: true }},(err) =>{
if(!err){
//add Thing Schema to Users collection
Thing = mongoose.model(admin);
var copy = mongoose.model('admin', admin,'User');
admin.save(function(err){});
return res.redirect('https://s3.ap-south-1.amazonaws.com/fw18/index.html');
}
Error:-
MissingSchemaError: Schema hasn't been registered for model correct me .
Http is a stateless protocol. To maintain state of the application you can use
1) session
2) cookies and
3) query string.
On your case, you can handle using session.
Store information to the session and get stored information from different routes.
Using: node/express/mongodb/mongoose
With the setup listed above, I have created my schema and model and can query as needed. What I'm wondering how to do though is, pass the express request.query object to Model.find() in mongoose to match and query the _id of a nested document. In this instance, the query may look something like:
http://domain.com/api/object._id=57902aeec07ffa2290f179fe
Where object is a nested object that exists elsewhere in the database. I can easily query other fields. _id is the only one giving an issue. It returns an empty array of matches.
Can this be done?
This is an example and not the ACTUAL schema but this gets the point across..
let Category = mongoose.Schema({
name: String
})
let Product = mongoose.Schema({
name: String,
description:String,
category:Category
})
// sample category..
{
_id:ObjectId("1234567890"),
name: 'Sample Category'
}
// sample product
{
_id:ObjectId("0987654321"),
name:'Sample Product',
description:'Sample Product Description',
category: {
_id:ObjectId("1234567890"),
name: 'Sample Category'
}
}
So, what I'm looking for is... if I have the following in express..
app.get('/products',function(req,res,next){
let query = req.query
ProductModel.find(query).exec(function(err,docs){
res.json(docs)
})
})
This would allow me to specify anything I want in the query parameters as a query. So I could..
http://domain.com/api/products?name=String
http://domain.com/api/products?description=String
http://domain.com/api/products?category.name=String
I can query by category.name like this, but I can't do:
http://domain.com/api/products?category._id=1234567890
This returns an empty array
Change your query to http://domain.com/api/object/57902aeec07ffa2290f179fe and try
app.get('/api/object/:_id', function(req, res) {
// req._id is Mongo Document Id
// change MyModel to your model name
MyModel.findOne( {'_id' : req._id }, function(err, doc){
// do smth with this document
console.log(doc);
});
});
or try this one
http://domain.com/api/object?id=57902aeec07ffa2290f179fe
app.get('/api/object', function(req, res) {
var id = req.param('id');
MyModel.findOne( {'_id' : id }, function(err, doc){
console.log(doc);
});
})
First of all increase your skills in getting URL and POST Parameters by this article.
Read official Express 4.x API Documentation
Never mind I feel ridiculous. It works just as I posted above.. after I fixed an error in my schema.
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);
Let's suppose I have a schema like this:
var Person = new Schema({
name: String
});
var Assignment = new Schema({
name: String,
person: ObjectID
});
If I delete a person, there can still be orphaned assignments left that reference a person that does not exist, which creates extraneous clutter in the database.
Is there a simple way to ensure that when a person is deleted, all corresponding references to that person will also be deleted?
You can add your own 'remove' Mongoose middleware on the Person schema to remove that person from all other documents that reference it. In your middleware function, this is the Person document that's being removed.
Person.pre('remove', function(next) {
// Remove all the assignment docs that reference the removed person.
this.model('Assignment').remove({ person: this._id }, next);
});
If by "simple" you mean "built-in", then no. MongoDB is not a relational database after all. You need to implement your own cleaning mechanism.
The remove() method is deprecated.
So using 'remove' in your Mongoose middleware is probably not best practice anymore.
Mongoose has created updates to provide hooks for deleteMany() and deleteOne().
You can those instead.
Person.pre('deleteMany', function(next) {
var person = this;
person.model('Assignment').deleteOne({ person: person._id }, next);
});
In case if anyone looking for the pre hook but for deleteOne and deleteMany functions this is a solution that works for me:
const mongoose = require('mongoose');
...
const PersonSchema = new mongoose.Schema({
name: {type: String},
assignments: [{type: mongoose.Schema.Types.ObjectId, ref: 'Assignment'}]
});
mongoose.model('Person', PersonSchema);
....
const AssignmentSchema = new mongoose.Schema({
name: {type: String},
person: {type: mongoose.Schema.Types.ObjectId, ref: 'Person'}
});
mongoose.model('Assignment', AssignmentSchema)
...
PersonSchema.pre('deleteOne', function (next) {
const personId = this.getQuery()["_id"];
mongoose.model("Assignment").deleteMany({'person': personId}, function (err, result) {
if (err) {
console.log(`[error] ${err}`);
next(err);
} else {
console.log('success');
next();
}
});
});
Invoking deleteOne function somewhere in service:
try {
const deleted = await Person.deleteOne({_id: id});
} catch(e) {
console.error(`[error] ${e}`);
throw Error('Error occurred while deleting Person');
}
You can leave the document as is, even when the referenced person document is deleted. Mongodb clears references which point to non-existing documents, this doesn't happen immediately after deleting the referenced document. Instead, when you perform action on the document, e.g., update. Moreover, even if you query the database before the references are cleared, the return is empty, instead of null value.
Second option is to use $unset operator as shown below.
{ $unset: { person: "<person id>"} }
Note the use of person id to represent the value of the reference in the query.
you can use soft delete. Do not delete person from Person Collection instead use isDelete boolean flag to true.
Use $pull. Suppose you have a structure like this.
Stuff Collection:
_id: ObjectId('63dd23c633c17a718c4c5db7')
item: "Item 1"
user: ObjectID('63de669153bc12ecb9081b9e')
User collection:
_id: ObjectId('63de669153bc12ecb9081b9e')
stuff: array[ObjectId('63dd23c633c17a718c4c5db7'), ObjectId('63de3a69715ec134e161b0ea')]
Then after you remove the stuff:
const stuff = Stuff.findById(req.params.id)
const user = User.findById(req.params.id)
await stuff.remove()
// here you can use $pull to update
await user.updateOne({
$pull: {
stuff: stuff.id
}
})
you can simply call the model that needs to be deleted and delete that document like this:
PS: This answer is not specific to the question schema.
const Profiles = require('./profile');
userModal.pre('deleteOne', function (next) {
const userId = this.getQuery()['_id'];
try {
Profiles.deleteOne({ user: userId }, next);
} catch (err) {
next(err);
}
});
// in user delete route
exports.deleteParticularUser = async (req, res, next) => {
try {
await User.deleteOne({
_id: req.params.id,
});
return res.status(200).json('user deleted');
} catch (error) {
console.log(`error`, error);
return next(error);
}
};
I'm writing an Express.js app that uses Mongoose ODM.
When a document is created/updated, I want it to automatically get some fields populated:
createdBy
createdOn
It seems to me that the right place to implement that would be in a Mongoose plugin that augments the document with those properties and provides defaults and/or mongoose middleware to populate the fields.
However, I have absolutely no idea how I could get the username from the session in my plugin.
Any suggestion?
/**
* A mongoose plugin to add mandatory 'createdBy' and 'createdOn' fields.
*/
module.exports = exports = function auditablePlugin (schema, options) {
schema.add({
createdBy: { type: String, required: true, 'default': user }
, createdOn: { type: Date, required: true, 'default': now }
});
};
var user = function(){
return 'user'; // HOW to get the user from the session ???
};
var now = function(){
return new Date;
};
You can't do this like this, bacause user function is added as a prototype method for this schema. In particular it is request/response independent. There is a hack however. If you have object obj of the type schema, then you can do
obj.session = req.session;
in request handler. Then you can access the session from the function. However this may lead to other issues ( for example running cron jobs on this collection ) and it looks like a very bad practice to me.
You can just do that manually, when a current user creates this schema object, can't you? Or create static method:
MySchema.statics.createObject = function ( user ) {
// create your object
var new_object = MySchema( ... );
// set necessary fields
new_object.createdBy = user.username;
}