What im doing:
When I call getData() the backend server .find() all my data.
My documents:
My test document has an _id a name and stuff fields. The stuff field contains the _id to the data document.
My data document has an _id and a age field
My goal:
When I send the data to the frontend I don´t want the stuff field to appear with the _id, I want it to appear with the age field from the correspondingdata.
What I have:
router.route('/data').get((req, res) => {
Test.find((err, aval) => {
if (err)
console.log(err);
else{
var result = [];
aval.forEach(e => {
var age;
// Get the age, only 1
Data.findById(e.stuff, 'age', function (err, a) {
age = a.age;
});
result.push({name: e.name, age: age});
});
res.json(result);
}
});
});
I find all the test documents then, for each one of them, I find the age and put the result in the array. Finaly I send the result array.
My problem:
The age field on my result array is always undefined, why? Any solutions?
UPDATE 1 - The schemas
The test schema
var TestSchema = new Schema(
{
stuff: {type: Schema.Types.ObjectId, ref: 'Data', required: true},
name: {type: String, required: true}
}
);
The data schema
var DataSchema = new Schema(
{
age: {type: Number, required: true}
}
);
router.route('/data').get((req, res) => {
Test.find({})
.populate('stuff')
.exec((err, aval) => {
if (err) console.log(err);
res.json(aval);
});
});
Mongoose model has a populate property that uses the value in the model attribute definition to get data matching the _id from another model.
It's a scop problem with your code try this out :
Data.findById(e.stuff, 'age', function (err, a) {
result.push({name: e.name, age: a.age});
});
But as a better solution think to use the Aggregation Framework
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 this Schema for a simple twitter app
const userSchema = new Schema ({
loginInfo: {
username: String,
email: String,
password: String
},
tweets: [{
content: String,
likes: Number,
comments: [{
owner: String,
content: String,
likes: Number
}]
}],
followers: [String],
following: [String]
})
and i want to make endpoint that return only the tweet that has the same _id that has been given as a params on the URL ..
I made that solution below and its working correctly but i believe there is a much better solution than this ..
const handleTweet = (User) => (req,res) => {
const { id } = req.params;
let theTweet = [];
User.findOne({ "tweets._id": id})
.then(user => {
user.tweets.forEach(tweet => {
if(tweet._id.toString() === id)
return theTweet.push(tweet)
})
res.json(theTweet)
})
.catch(err => res.json(err))
}
module.exports = handleTweet;
One more question : Is it better to make nested schemas like this or making a different models for each schema (in this case schema for User and another one for Tweets) ?
You should make the tweets into a different collection since you are querying based on that, and then you can use autopopulate when you need it.
Also instead of the foreach you could use Array.prototype.find
Hope this helps!
You can use the $push & findOneAndUpdate methods from mongoose. You can modify your example to be like this:
User.findOneAndUpdate(id, { $push: { tweets: req.body.tweet } }, {new: true})
.then((record) => {
res.status(200).send(record);
})
.catch(() => {
throw new Error("An error occurred");
});
Notice the {new: true} option, it makes the findOneAndUpdate method to return the record with the edit.
For your second question, it's recommended to split the modals to make your code more readable, maintainable and easy to understand.
Users are able to post items which other users can request. So, a user creates one item and many users can request it. So, I thought the best way would be to put an array of users into the product schema for who has requested it. And for now I just want to store that users ID and first name. Here is the schema:
const Schema = mongoose.Schema;
const productSchema = new Schema({
title: {
type: String,
required: true
},
category: {
type: String,
required: true
},
description: {
type: String,
required: true
},
userId: {
type: Schema.Types.ObjectId,
ref: 'User',
required: true
},
requests: [
{
userId: {type: Object},
firstName: {type: String}
}
],
});
module.exports = mongoose.model('Product', productSchema);
In my controller I am first finding the item and then calling save().
exports.postRequest = (req, res, next) => {
const productId = req.body.productId;
const userId = req.body.userId;
const firstName = req.body.firstName;
const data = {userId: userId, firstName: firstName};
Product.findById(productId).then(product => {
product.requests.push(data);
return product
.save()
.then(() => {
res.status(200).json({ message: "success" });
})
.catch(err => {
res.status(500).json({message: 'Something went wrong'});
});
});
};
Firstly, is it okay to do it like this? I found a few posts about this but they don't find and call save, they use findByIdAndUpdate() and $push. Is it 'wrong' to do it how I have done it? This is the second way I tried it and I get the same result in the database:
exports.postRequest = (req, res, next) => {
const productId = req.body.productId;
const userId = req.body.userId;
const firstName = req.body.firstName;
const data = {userId: userId, firstName: firstName};
Product.findByIdAndUpdate(productId, {
$push: {requests: data}
})
.then(() => {
console.log('succes');
})
.catch(err => {
console.log(err);
})
};
And secondly, if you look at the screen shot is the data in the correct format and structure? I don't know why there is _id in there as well instead of just the user ID and first name.
Normally, Developers will save only the reference of other collection(users) in the collection(product). In addition, you had saved username also. Thats fine.
Both of your methods work. But, second method has been added in MongoDB exactly for your specific need. So, no harm in using second method.
There is nothing wrong doing it the way you have done it. using save after querying gives you the chance to validate some things in the data as well for one.
and you can add additional fields as well (if included in the Schema). for an example if your current json return doesn't have a field called last_name then you can add that and save the doc as well so that's a benefit..
When using findById() you don't actually have the power to make a change other than what you program it to do
One thing I noticed.. In your Schema, after you compile it using mongoose.modal()
export the compiled model so that you can use it everywhere it's required using import. like this..
const Product = module.exports = mongoose.model('Product', productSchema);
The schema of my Sample model is:-
var nameSchema = new mongoose.Schema({
firstname:String,
lastname:String
})
var sampleSchema= new mongoose.Schema({
number: {
type: String
},
name :{
type : [nameSchema]
}
});
I am trying to update the first and last name by searching them by their number property by making use of Sample.findOne({number:number}). And i am performing the update operation in the following manner:-
module.exports.updateNumber = function(req, res){
var number= req.body.number;
var lname= req.body.lname;
var fname= req.body.fname;
Sample
.findOne({number:number})
.select('name')
.exec(function(err, doc){
console.log(doc)
var this_id;
var thisService = doc.name.id('this_id');
thisService.firstname=fname;
thisService.lastname=lname;
doc.save(function(err, update) {
if (err) {
res
.status(500)
.json(err);
} else {
res
res.render('done')
}
});
})
}
If i console log the output i got is:
{ _id: 5bc5d71f47ff14361c0639d1,
name:
[ { _id: 5bc5d71f47ff14361c0639d2,
firstname: 'firstname',
lastname: 'lastname' } ] }
Is there any way, i could store _id: 5bc5d71f47ff14361c0639d2 in 'this_id' variable, so that this updation would be possible
name is an array, so if you want the first _id then name[0]._id would suffice, if you want an array of all values for _id in name, then name.map((person) => person._id) would give you an array of _id
However, more details about the context of this object would help give a better answer.
I have a schema article defined as:
var ArticleSchema = new Schema({
title: String,
content: String,
creator: {
type: Schema.ObjectId,
ref: 'User'
}
})
And user schema:
var UserSchema = new Schema({
type: String, //editor, admin, normal
username: String,
password: String,
})
I need to query all the article created by editor, i.e. in sql language
select Article.title as title, Article.content as content
from Article inner join User
on Article.creator = User._id
where User.type = 'editor'
This is what I have tried
exports.listArticle = function(req, res, next) {
var creatorType = req.query.creatorType
var criteria = {}
if (creatorType)
criteria = {'creator.type': creatorType}
Article.find(criteria).populate('creator').exec(function(err, articles) {
if (err)
return next(err)
//ok to send the array of mongoose model, will be stringified, each toJSON is called
return res.json(articles)
})
}
The returned articles is an empty array []
I also tried Article.populate('creator').find(criteria), also not working with error:
utils.populate: invalid path. Expected string. Got typeof `undefined`
There is no concept of joins in MongoDB, as it is a not a relational database.
The populate method is actually a feature of Mongoose and internally uses multiple queries to replace the referred field.
This will have to be done using a multi-part query, first on the User collection, then on the Article collection.
exports.listArticle = function(req, res, next) {
var creatorType = req.query.creatorType
var criteria = {}
if (creatorType)
criteria = {'type': creatorType}
User.distinct('_id', criteria, function (err, userIds) {
if (err) return next(err);
Article.find({creator: {$in: userIds}}).populate('creator').exec(function(err, articles) {
if (err)
return next(err)
//ok to send the array of mongoose model, will be stringified, each toJSON is called
return res.json(articles)
})
})
}