my mongodb structure
//First user
_id:ObjectId("12345")
name:"prudhvi"
authors:Array
0:Object
authorId:"77777"
authortitle:"medicine"
1:Object
authorId:"66666"
authortitle:"Hospital"
//second user
_id:ObjectId("67890")
name:"venkat"
authors:Array
0:Object
authorId:"55555"
authortitle:"Doctor"
1:Object
authorId:"44444"
authortitle:"Nurse"
Can someone please help here i have two users, On that i need to get only the latest object of authors array. Here my latest Object is 1:Object, If in case one more is added, I need to get 2:Object of data of all users.
I tried like this but i am getting all objects of authors array, But i need to get latest object
userRouter.post('/getAuthors', function (req, res) {
Collections.user.find(req.body.user, function (err, result) {
if (err) res.status(500).send("There was a problem finding the user");
if (result.length > 0) {
res.status(200).send(result[0].authors);
}
}).select({ "authors": 1 });
});
Try using this
Collections.user.find().limit(1).sort({$natural:-1})
Take a look at $natural and cursor.sort
In your mongoose schema you can set timestamps. it will automatically set createdAt time stamp when you create a object from that schema and if you edit that particular object it set updatedAt timestamp.
As a example schema,
const mongoose = require('mongoose');
const markSchema = mongoose.Schema({
_id: mongoose.Schema.Types.ObjectId,
mark: { type: Number },
student: { type: String },
},{
timestamps: true
});
module.exports = mongoose.model('Mark', markSchema);
like this you can set timestamps.
Related
I am at my wits end with something that is seemingly straightforward:
I need to be able to push new gifts into the Events Array under the specific user. Because each event will have numerous gifts added, I want to keep them all under the user, as they are the one creating the event, and the gifts will live inside of their event where they belong.
The PROBLEM is: when I use the mongoose method 'findByIdAndUpdate', I can only find the main user, and from there, push an event to the events array. What I NEED to be able to do: push gifts to a specific event under that user. I am using mongoose Subdocuments. See my schema below and how I have a subdocument schema (EventSchema) inside of the main user schema, and a subdocument (gift) schema inside the event schema.
SCHEMA:
const Schema = mongoose.Schema;
let giftArr = new Schema({
giftname: String,
giftlink: String,
claimed: Boolean,
claimee: String
})
let eventSchema = new Schema({
eventname: String,
eventowner: String,
date: {
type: Date,
default: Date.now
},
attendees: [
{
attendeename: String
}
],
gift: [giftArr]
})
let userSchema = new Schema({
username: String,
email: { type: String, required: false },
events: [eventSchema]
});
Here are my controllers for my POST & GET routes:
export const insertEventsById = ((req, res) => {
const update = { $push: { events: req.body } }
const id = req.params.userID
Gift.findByIdAndUpdate(id, update, (err, data) => {
if (err) {
console.log(err);
} else {
res.json(data)
console.log(data);
}
})
})
export const getUserById = (req, res) => {
Gift.findById(req.params.userID, (err, user) => {
if(err){
res.send(err)
}
res.json(user)
})
}
To further illustrate, here is my postman GET request for a USER. I can push to the 'events' array (red arrow) as my findByIdAndUpdate method shows above, but when I attempt to go one nested level deeper, into the gift array (green arrow), I cannot find any documentation on that.
I been up and down the mongoose subdocuments and queries pages, and I cannot find a method that will pull specifically the '_id' of the particular event I need. I have even tried the methods on the embedded schemas to specifically look for _id's that way.
Can someone point out where I am going wrong here? Thanks in advance...as always fellow Stacks.
I have a User schema with a collections property that holds collection objects. These collection objects have a property called items that is an array of objects.
//User Schema
const UserSchema = new mongoose.Schema({
username: {
type: String,
required : true,
},
password: {
type: String,
required: true
},
collections: [{type : mongoose.Schema.Types.ObjectId, ref: 'Collection'}]
});
//Collection Schema
const CollectionSchema = new mongoose.Schema({
items : [{type : mongoose.Schema.Types.ObjectId, ref: 'Item'}]
});
//Item Schema
const ItemSchema = new mongoose.Schema({
title: {
type: String,
required: true
});
Using the code below, I tried creating and pushing a new Item Schema into the first collection object. I pass the _id of the collection object I want to update using the findById function. After finding the collection with my id, I simply just push a Item Schema into the collection object's items array. I get the res.status(200) yet my items array is never updated. Does anyone else have this issue? Thank you for you help.
userRouter.post('/addItem', passport.authenticate('jwt', {session: false}), (req, res) => {
const item = new Item(req.body)
item.save(err => {
if(err)
res.status(500).json({message: {msgBody: "Error has occured", msgError: true }});
else {
Collection.findById(req.body.search, function(err, coll){
coll.items.push(item);
req.user.save(err => {
if(err)
res.status(500).json(err)
else{
res.status(200).json(coll)
}
})
})
}
})
});
You don´t perform any update operation on the Collection with the newly created Item document in the database.
Add the created Item document by using the $addToSet operator (https://docs.mongodb.com/manual/reference/operator/update/addToSet/) to the items property in Collection (I would suggest by using mongoose findByIdAndUpdate method or updateOne method).
It would be something like this using callbacks:
Collection.findByIdAndUpdate(req.body.search, { $addToSet: {items: item._id}}, callback);
If you have multiple Item documents which you need to insert into Collection, you can use $addToSet in combination with the $each operator (https://docs.mongodb.com/manual/reference/operator/update/each/).
I originally have these two schemas:
var UserSchema = new Schema({
first: String,
last: String
});
var SaleSchema = new Schema({
createdAt: Date,
registeredBy: { type: Schema.ObjectId, ref: 'User' }
});
But I want to edit my SaleSchema to save the user name instead of the ID, so I changed it for:
var SaleSchema = new Schema({
createdAt: Date,
registeredBy: String
});
Next, I wanted to edit all the Sales documents and replace the user IDs on registeredBy for the user's full name, but I can't seem to be able to perform a find query for the old ID's.
Long story short, this query returns no matches on mongoose, but it works perfectly using the mongo console:
Mongoose
Sale.find({ registeredBy: '57ea0cbb47431f0b43b87d42' })
.then(results => res.json(results))
.catch(err => res.status(500).json(err));
// result: []
MongoDB console
db.sales.find({ registeredBy: '57ea0cbb47431f0b43b87d42' })
// result: 8 elements
After I modify my schema's property back to ObjectId, the mongoose query works again. Since I need to migrate to a new datatype, I want to be able to query and store both types of values. Is this possible?
Good question this is a complicated edge case. I am not super familiar with Mongoose specifically, but one way to do this would be to migrate your data at a lower level. For example, create a mongo script that uses the low-level mongo API to do the migration, something along the lines of:
db.sales.find().forEach(function(doc){
var user = db.users.find({ _id: doc.registeredBy });
db.sales.update({ _id: doc._id, }, {
$set: { registeredBy: user.first + ' ' + user.last }
});
});
This is similar to what a module like https://github.com/balmasi/migrate-mongoose does, but I've personally found it easier to use mongo scripts on the cli directly.
mongo < sale-schema-migration.js
Due to a management decision, we are using userId for the users collection, postId for the posts collection, and topicId for the topics collection, instead of '_id' for each collection as the unique identifier.
This causes a few problems getting started - one of the problems I have encountered is with upserts -
Using Mongoose, we have a schema that restricts userId to be a unique value - but when doing an update on a user model, with upsert set to true, MongoDB appears to only look at the ObjectIds of a collection to see if the same one exists - it doesn't check to see if a model already exists with the same userId - therefore Mongo does an insert instead of an update.
let me illustrate this with some data:
let's say the user's collection has one document:
{
_id:'561b0fad638e99481ab6d84a'
userId:3,
name:'foo'
}
we then run:
User.update({userId:3},{"$set":{name:'bar'},{upsert:true},function(err,resp){
if(err){
// "errMessage": "insertDocument :: caused by :: 11000 E11000 duplicate key error index: app42153482.users.$userId_1 dup key: { : 3 }",
}
});
one would think that MongoDB would find the existing document with userId:3 and udpate it, so there must be something I am doing wrong since it's giving me the duplicate key error?
Typically the default value ObjectId is more ideal for the _id. Here, in this situation you can either override the default _id or you can have your own field for id(like userId in your case).
Use a separate counters collection to track the last number sequence used. The _id field contains the sequence name and the seq field contains the last value of the sequence.
Insert into the counters collection, the initial value for the userid:
db.counters.insert( {
_id: "userid",
seq: 0 } )
Create a getNextSequence function that accepts a name of the sequence. The function uses the findAndModify() method to atomically increment the seq value and return this new value:
function getNextSequence(name) {
var ret = db.counters.findAndModify(
{
query: { _id: name },
update: { $inc: { seq: 1 } },
new: true
}
);
return ret.seq;
}
Use this getNextSequence() function during insert().
db.users.insert(
{
_id: getNextSequence("userid"),
name: "Sarah C."
}
)
db.users.insert(
{
_id: getNextSequence("userid"),
name: "Bob D."
}
)
This way you can maintain as many sequences as you want in the same counter collection. For the upsert issue, check out the Optimistic Loop block in this link Create an auto-increment sequence field.
The second approach is to use a mongoose middleware like mongodb-autoincrement.
Hope it helps.
I don't know which versions of MongoDB and Mongoose you are using, but I couldn't reproduce your problem with MongoDB 3.0 and Mongoose 4.1.10.
I made a sample for you which will create and save a new user, update (using upsert) it, and create another one through an upsert. Try running this code:
"use strict";
var mongoose=require("mongoose");
var Schema = require('mongoose').Schema;
var ObjectId = mongoose.Schema.Types.ObjectId;
// Connect to test
mongoose.connect("mongodb://localhost:27017/test");
// Lets create your schema
var userSchema = new Schema({
_id: ObjectId,
userId: {type: Number, unique: true },
name: String
});
var User = mongoose.model("User", userSchema, "Users");
User.remove() // Let's prune our collection to start clean
.then( function() {
// Create our sample record
var myUser = new User({
_id:'561b0fad638e99481ab6d84a',
userId:3,
name:'foo'
});
return myUser.save();
})
.then( function() {
// Now its time to update (upsert userId 3)
return User.update({userId:3},{"$set":{name:'bar'}},{upsert:true});
})
.then( function() {
// Now its time to insert (upsert userId 4)
return User.update({userId:4},{"$set":{name:'bee'}},{upsert:true});
})
.then( function() {
// Lets show what we have inserted
return User.find().then(function(data) {console.log(data)});
})
.catch( function(err) {
// Show errors if anything goes wrong
console.error("ERROR", err);
})
.then( function() {
mongoose.disconnect();
});
Following the documentation (of MongoDB 3.0) upsert:true will only not insert a non-existing document if your query conditions match on the _id field.
See: https://docs.mongodb.org/manual/reference/method/db.collection.update/#mongodb30-upsert-id
Why are you not using the user_name for a user as unique id?
Because auto-incrementing fields as ids are a bad practice to use in a mongodb environment, especially if you want to use sharding
=> all your inserts will occur on the latest shard
=> the mongodb cluster will have to rebalance often / redistribute the data around.
(Currently this will not occur on your system as you still use the generated _id field)
You can off course also create a unique index on the user_id field:
https://docs.mongodb.org/manual/core/index-unique/#index-type-unique
I have this Mongoose Schema.
var mongoose = require('mongoose')
, dev = require('../db').dev();
var schema = new mongoose.Schema({
date: {
type: Date,
default: Date.now()
},
company: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Company'
},
questionnaire: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Questionnaire'
}
});
module.exports = dev.model('Survey', schema);
I want to find only the surveys which have a specific company id. How do I do that? I tried (with my Express handler):
app.get('/survey', function(req, res) {
Survey.find({ company: req.query.company })
.populate('questionnaire')
.exec(function(err, surveys) {
return res.json(surveys);
});
});
In your latest comment you say that the company field of the Surveys collection is actually a string and not and ObjectId and that's why this isn't working. Because your schema definition declares company as an ObjectId, Mongoose will cast your req.query.company value to an ObjectId and then query for documents in Surveys where their company property is an ObjectId with the same value. So if company is a string in the database it won't match.
If you update the company values in Surveys to be ObjectIds instead of strings then this will work.
have you tried 'company._id
app.get ('/survey', function (req, res) {
Survey.find ({ 'company._id': req.query.company }).populate ('questionnaire').exec (function (err, surveys) {
return res.json (surveys);
});
});
What worked for me (and it is hinted in the accepted answer) was to make sure that the documents are created through mongoose (i.e through your express server) because this will force the schema onto them, and thus the ids will be stored as objectIds.
Initially I had created a document manually through the database using the objectIds as simple strings, and this causes the query not to work because mongo casts the id (from your server) as an ObjectId.