Mongodb Ref dynamic populate with grapqhl? - mongodb

I have to decide whether to populate or not according to the query request, but I don't know how to do it.
So Example
If my model User is looks like this
below syntax is from typegoose and typegraphql
class User {
#Field()
#prop()
name: string;
#Field()
#prop(ref:"House")
house: Ref<House>
}
And here is two diffent query
Query1
user {
name
}
Query2
user {
name
house {
location
}
}
And in the resolver
User: () => {
const user = UserModel.find(blahblah)**.populate("house")**
return user
}
Query1 dose not need populate
but Query2 need
in same resolver!
I want to decide whether to populate or not depending on the requirements of the query.
I can't decide whether to populate or not without knowing what is the actual query was in resolver.
I found very similar question in stackoverflow
But there is not proper answer...
Solving relationships in Mongoose and GraphQL

i dont know much about graphql, but i think there is some method to get if that path is requested, so the following should work:
let query = Model.find(basicQuery);
if (req.path) { // replace this with graphql's method to get if the path is requested
query = query.populate(yourPath);
}
const doc = await query.exec();
PS: but as an comment already noted, i think there is some better method to do this in graphql (another resolver?)

Related

Format response from mongoose into a model

How do you go about formatting the data response from mongoose? For a simple Post Schema
const postSchema = new mongoose.Schema({
title: {
type: String,
required: true,
}
},{
timestamps: true
});
Whenever I do a GET request to find all the post, It returns me all its fields including _id and __v in which I wouldn't want to return those fields in an API.
Is there a way I would select only certain fields that I would want to return?
As far as I've found was that I could set a second parameter of title onto my query and it would return only the _id and title.
const post = await Post.find({},'title');
I find the method above isn't the proper way to filter fields in cases in the future where the values are deeply nested object and we would like to pick out certain values.
Is there perhaps a way to create a Model/Class and pick the fields based on the Model/Class and return the respond?
You can use select from mongoose.
You can either select only the fields you want.
var find = await model.find({}).select("my_field")
Or not show the fields you don't want
var find = await model.find({}).select("-my_field")
Check the documentation

elemMatch for fields in different levels

I'm asking this question after trying solve this problem all day long.
I want to get my users address by userId and by addressId. Since I receive data from post requests, I need to ensure that the query contains both userId and addressId in order to avoid security problems. The result of the query below returns all addresses from my user, instead of just the address containing the correct addressId.
async getUserAddress(_id: string, addressId: string) {
const user = await this.userModel.findOne(
{
_id,
addresses: {
$elemMatch: {
addressId: Types.ObjectId(addressId)
}
}
}
)
if (!user) {
throw new NotFoundException();
}
return user.addresses[0];
}
Since is impossible to use $elemMatch in different document levels, or even at the top level of the query, I find no better way to make this query without using filters. Are there any insights?
Tks in advance

Mongoose: Delete Item - First One always gets deleted

I am completely new to the fields of Mongoose and MongoDB.
I am currently trying trying to remove one element from my database.
This is my code so far:
My issueModel:
var mongoose = require('mongoose'); // loading module for mongoose
var db = mongoose.connect('mongodb://localhost/issuedb');
var issueSchema = new mongoose.Schema({
title: String,
description: String,
priority: String,
status: String
});
// Constructor Function:
var issueModel = mongoose.model('issues', issueSchema); // have to give the
name of the collection where the element should be stored + Schema
// Export this Construction Function for this Module:
module.exports = issueModel; // careful: module != model !
My post method for using the delete method:
// creating the router for deleting one item:
router.post('/delete/:id', (req, res) => {
console.log(req.params.id);
issueModel.remove({id: req.params.ObjectId})
.setOptions({ single: true }).exec(function (err, deleted) {})
.then(issues => res.render('issue', {issues: issues}));
The thing i would like to do here is using the object id - which is correctly stored in req.params.ObjectID according to my console.log, and deleting the corresponding object.
But currently , when i have got a table with about 3-4 entries, always the first one gets deleted. Why is that? I am really TOTALLY new and really tried searching a lot, but i could not find any solution until now. I am happy about any tips that would help me.
What am i doing wrong?
The ID in the URL and the Object.ID are the same! Why is the first object deleted then, not the second or the third?
I am hopeless right now.
I also read about the remove() option not being really used in todays time. But we were told at university to use this method right now.
I also tried findOneByID and delete methods i found in the mongoose database.
If you need any more code please let me know!
You can use one of the convenience methods for this: findByIdAndRemove:
issueModel.findByIdAndRemove(req.params.ObjectId, function(err) {
if (err) { ... failed }
});
This will remove a whole document matching the ID which I think its what you want, if you want to a remove property from a document that's a different query.
If you don't use one of the convenience methods which just take IDs (have ById in them), then you have to convert your ID from a string to an ObjectId:
const { ObjectId } = require('mongodb');
issueModel.remove({ id: ObjectId(req.params.ObjectId) }).setOptions({ single: true })

Mongoose - populate return _id only instead of a Object [duplicate]

In Mongoose, I can use a query populate to populate additional fields after a query. I can also populate multiple paths, such as
Person.find({})
.populate('books movie', 'title pages director')
.exec()
However, this would generate a lookup on book gathering the fields for title, pages and director - and also a lookup on movie gathering the fields for title, pages and director as well. What I want is to get title and pages from books only, and director from movie. I could do something like this:
Person.find({})
.populate('books', 'title pages')
.populate('movie', 'director')
.exec()
which gives me the expected result and queries.
But is there any way to have the behavior of the second snippet using a similar "single line" syntax like the first snippet? The reason for that, is that I want to programmatically determine the arguments for the populate function and feed it in. I cannot do that for multiple populate calls.
After looking into the sourcecode of mongoose, I solved this with:
var populateQuery = [{path:'books', select:'title pages'}, {path:'movie', select:'director'}];
Person.find({})
.populate(populateQuery)
.execPopulate()
you can also do something like below:
{path:'user',select:['key1','key2']}
You achieve that by simply passing object or array of objects to populate() method.
const query = [
{
path:'books',
select:'title pages'
},
{
path:'movie',
select:'director'
}
];
const result = await Person.find().populate(query).lean();
Consider that lean() method is optional, it just returns raw json rather than mongoose object and makes code execution a little bit faster! Don't forget to make your function (callback) async!
This is how it's done based on the Mongoose JS documentation http://mongoosejs.com/docs/populate.html
Let's say you have a BookCollection schema which contains users and books
In order to perform a query and get all the BookCollections with its related users and books you would do this
models.BookCollection
.find({})
.populate('user')
.populate('books')
.lean()
.exec(function (err, bookcollection) {
if (err) return console.error(err);
try {
mongoose.connection.close();
res.render('viewbookcollection', { content: bookcollection});
} catch (e) {
console.log("errror getting bookcollection"+e);
}
//Your Schema must include path
let createdData =Person.create(dataYouWant)
await createdData.populate([{path:'books', select:'title pages'},{path:'movie', select:'director'}])

Query sailsjs blueprint endpoints by id array using request

I'm using the request library to make calls from one sails app to another one which exposes the default blueprint endpoints. It works fine when I query by non-id fields, but I need to run some queries by passing id arrays. The problem is that the moment you provide an id, only the first id is considered, effectively not allowing this kind of query.
Is there a way to get around this? I could switch over to another attribute if all else fails but I need to know if there is a proper way around this.
Here's how I'm querying:
var idArr = [];//array of ids
var queryParams = { id: idArr };
var options: {
//headers, method and url here
json: queryParams
};
request(options, function(err, response, body){
if (err) return next(err);
return next(null, body);
});
Thanks in advance.
Sails blueprint APIs allow you to use the same waterline query langauge that you would otherwise use in code.
You can directly pass the array of id's in the get call to receive the objects as follows
GET /city?where={"id":[1, 2]}
Refer here for more.
Have fun!
Alright, I switched to a hacky solution to get moving.
For all models that needed querying by id arrays, I added a secondary attribute to the model. Let's call it code. Then, in afterCreate(), I updated code and set it equal to the id. This incurs an additional database call, but it's fine since it's called just once - when the object is created.
Here's the code.
module.exports = {
attributes: {
code: {
type: 'string'//the secondary attribute
},
// other attributes
},
afterCreate: function (newObj, next) {
Model.update({ id: newObj.id }, { code: newObj.id }, next);
}
}
Note that newObj isn't a Model object as even I was led to believe. So we cannot simply update its code and call newObj.save().
After this, in the queries having id arrays, substituting id with code makes them work as expected!