I have been looking the issue I have I found so many problems related to my issue but It did not work for me. I don't know what I am missing!
In my schema I did it like this:
student: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Student',
required: true,
},
In the logic I did like this:
const agg = await MarksModel.aggregate([
{
$match: {
student: studentObj._id,
course: courseObj._id,
},
},
{
$group: {
_id: {
subject: '$subject',
course: '$course',
student: '$student',
semester: '$semester',
},
totalTheoryMarks: { $sum: '$theoryMarks' },
totalPracticalMarks: { $sum: '$practicalMarks' },
},
},
{
$lookup: {
from: 'Student', // I tried students, student, Students & Student.
localField: 'student',
foreignField: '_id',
as: 'student',
},
},
])
Everything is fine but I always return some output like this:
[
{
_id: {
subject: 60c700aaf6deb877000028c4,
course: 60b8fe0fccbe980f70e6542d,
student: 60c1f2a7f12ac51544035a12,
semester: 3
},
totalTheoryMarks: 30,
totalPracticalMarks: 30,
student: [] // This is the issue I have
}
]
I solved my issue by swiping $lookup and $group. $group uses a reference array from $lookup which is from top to bottom.
Related
I am currently working on a project that has the following schema using mongoose.
User schema
const userSchema = {
name: string
email: string
medicalVisits: [{type: Schema.ObjectId, ref: "records"}]
createdAt: Date
}
Records schema
const recordSchema = {
medication: [String],
rating: Number
user: [{type: Schema.ObjectId, ref: "user"}]
tests: [{type: Schema.ObjectId, ref: "tests"}]
createdAt: Date
}
Tests schema
testScore: Number
answers: Object
user: [{type: Schema.ObjectId, ref: "user"}]
createdAt: Date
From the little schema above, I have a setup where a patient can take tests multiple times and their respective tests are saved in the Tests collection. Also, the date is recorded for all tests they take. A doctor can request to see a patient's record, in this case, the patient has only one record document that has their tests records embedded in them. Currently, I am faced with the problem of getting a patient's newest and oldest test score alongside their initial details.
I can do a mongoose populate to get all information regarding a user, e.g
await User.findById(userId).populate({
path: "medicalVisits"
model: "records"
populate: {
path: "tests"
model: "test"
}
})
And that operation returns the patient's record and all the tests they have taken since they signed up to date. But when I make such a call to the Database, I just want to retrieve the patient's newest and oldest score. In other words, I want to get the patients, Initial test score, and their most recent test score. I am new to Mongoose aggregation, I tried to use the Mongoose aggregate function, but it returns an empty array, I guess I am missing something.
Currently, this is what my aggregate pipeline looks like.
const user = await Doctor.aggregate([
{ $match: { _id: docId } },
{
$lookup: {
from: "users",
localField: "patients",
foreignField: "_id",
as: "patients",
},
},
{ $unwind: "$patients" },
{ $unwind: "$patients.medicalVisits" },
{
$lookup: {
from: "records",
localField: "patients.user",
foreignField: "_id",
as: "patientRecord",
},
},
{ $unwind: "$patientRecord" },
// { $sort: { createdAt: 1 } },
{
$group: {
_id: docId,
user: { $last: "$patients" },
record: { $last: "$patientRecord"}
},
},
]);
return user[0];
From the above snippet, my intention is:
given a doctor Id, they can see a list of their patients and also see their newest and oldest test score.
Expected Output
const output = {
userId: 6e12euido....
name: "John doe"
email: "john#john.com"
rating: 2
initialTestScore: 10
recentTestScore: 30
}
How do I go about this? Or what could be a better alternative? Thank you very much.
tried my best to understand your case, and I think your aggregation pipeline should be like:
const patientsWithNewestRecord = await Doctor.aggregate([
{ $match: { _id: docId } },
{
$lookup: {
from: "users",
localField: "patients",
foreignField: "_id",
as: "patients",
},
},
// one patient, per doc
{ $unwind: "$patients" },
// one patient with all his/her visit records, per doc
{
$lookup: {
from: "records",
localField: "patients.medicalVisits",
foreignField: "_id",
as: "patientRecords",
},
},
// one patient with one visit record, per doc
{ $unwind: "$patientRecords" },
// sort by patient first, createdAt second
{ $sort: { 'patientRecords.user': 1, 'patientRecords.createdAt': 1 } },
{
$group: {
_id: { patient: '$patientRecords.user' },
user: { $last: "$patients" },
record: { $last: "$patientRecords"}
},
},
]);
this pipeline return a list of a doctor's patients and also see their newest test record. Oldest test record should be in similar war.
Based on these collections (as I understand them from your question):
// doctor collection:
{ _id: "doc1", patients: ["user1"] }
// user collection:
{
_id: "user1", name: "John", email: "john#gmail.com",
medicalVisits: ["record1", "record2"]
}
// record collection:
{ _id: "record1", rating: 2, tests: ["test1", "test2"] }
{ _id: "record2", rating: 4, tests: ["test3"] }
// test collection:
{ _id: "test1", testScore: 12, createdAt: ISODate("2021-12-04") }
{ _id: "test2", testScore: 9, createdAt: ISODate("2021-12-05") }
{ _id: "test3", testScore: 15, createdAt: ISODate("2021-12-24") }
we can apply:
db.doctor.aggregate([
{ $match: { _id: "doc1" } }
{ $lookup: {
from: "user",
localField: "patients", foreignField: "_id",
as: "patients"
}},
{ $unwind: "$patients" }, { $unwind: "$patients.medicalVisits" },
{ $lookup: {
from: "record",
localField: "patients.medicalVisits", foreignField: "_id",
as: "records"
}},
{ $unwind: "$records" }, { $unwind: "$records.tests" },
{ $lookup: {
from: "test",
localField: "records.tests", foreignField: "_id",
as: "tests"
}},
{ $unwind: "$tests" },
{ $sort: { "tests.createdAt": 1 } },
{ $group: {
_id: "$patients._id",
name: { $first: "$patients.name" },
email: { $first: "$patients.email" },
rating: { $first: "$records.rating" },
initialTestScore: { $first: "$tests.testScore" },
recentTestScore: { $last: "$tests.testScore" }
}},
{ $set: { "userId": "$_id" } }, { $unset: "_id" }
])
in order to extract:
{
userId: "user1",
name: "John",
email: "john#gmail.com",
rating: 2,
initialTestScore: 12,
recentTestScore: 15
}
Differences compared to your query:
I $lookup the test collection as it seems you information from there to get both test dates and test scores.
I $sort by test date (createdAt) before the $group by user such that we'll be able to define the right order for selecting the $first and $last test scores.
I extract user's information by using a $first on each group on user's field (since all unwind records for a given user have the same user information): for instance email: { $first: "$patients.email" }
I extract the $first and $last test scores for a user as defined by the $sort order: initialTestScore: { $first: "$tests.testScore" } and recentTestScore: { $last: "$tests.testScore" }.
I finally $set/$unset to rename the _id field into userId
I would suggest to do the following once you have the userId / patientId:
Get their tests (all) from the database in a sorted order
Take the first and last element of the array for your initial and final test report based on the sorting order you have applied (ascending or descending)
If you can just retrieve the user details and all the tests without any sorting, then you can proceed the following way:
Run a loop through all the tests and sort the tests according to test date.
Take the first and last element of the array for your initial and final test report based on the sorting order you have applied (ascending or descending)
You will not be performing the operations on DB end, so there might be a minor speed issue, but the difference would still come out to be in milliseconds unless a user takes a billion tests.
Let me know if this helps, let me know if it doesn't
I have the following schema:
const UserQualificationSchema = new Schema(
{
user: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User',
},
qualification: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Qualification',
},
expiry_date: {
type: Date
}
}
const QualificationSchema = new Schema(
{
fleet: {
type: [String], // Eg ["FleetA", "FleetB", "FleetC"]
required: true,
}
}
I am searching the UserQualifications with filters in a table, to search them by fleet, qualification or expiry date. I so far have the following aggregate:
db.UserQualifications.aggregate([{
{
$lookup: {
from: 'qualifications',
localField: 'qualification',
foreignField: '_id',
as: 'qualification',
},
},
{
$unwind: '$qualification',
},
{
$match: {
$and: [
'qualification.fleet': {
$in: ["Fleet A", "Fleet C"], // This works
},
expiry_date: {
$lt: req.body.expiry_date, // This works
},
qualification: { // Also tried 'qualification._id'
$in: ["6033e4129070031c07fbbf29"] // Adding this returns blank array
}
]
},
}
}])
Filtering by fleet, and expiry date both work, independently and in combination, however when adding by the qualification ID, it returns blank despite the ID's being sent in being valid.
Am i missing something here?
Looking at your schema I can infer that qualification in ObjectId and in the query you are passing only the string value of ObjectId. You can pass the ObjectId to get your expected output
db.UserQualifications.aggregate([
{
$lookup: {
from: "Qualifications",
localField: "qualification",
foreignField: "_id",
as: "qualification",
},
},
{
$unwind: "$qualification",
},
{
$match: {
"qualification.fleet": {
$in: [
"FleetA",
"FleetC"
],
},
expiry_date: {
$lt: 30 // some dummy value to make it work
},
"qualification._id": {
$in: [
// some dummy value to make it work
ObjectId("5a934e000102030405000000")
]
}
},
}
])
I have created a playground with some dummy data to test the query: Mongo Playground
Also, In $match stage there is no need to combine query explicitly in $and as by default behaviour will be same as $and only so I have remove that part in my query
I am trying to group by products in my sales collection and add their totals to know which are the best selling products of my app.
MONGOOSE MODEL
const mongoose = require('mongoose');
const DHCustomerinvoiceSchema = mongoose.Schema({
Saledetail: {
type: Array,
required: true
},
date:{
type: Date,
required: true
},
total:{
type: Number,
required: true
},
pay:{
type: Number,
required: true,
default: 0
},
topay:{
type: Number,
required: true
},
user:{
type: mongoose.Schema.Types.ObjectId,
required: true,
ref: 'UserDH'
},
customer:{
type: mongoose.Schema.Types.ObjectId,
required: true,
ref: 'DHcontacto'
},
state:{
type: String,
default: "OWED"
},
created:{
type: Date,
default: Date.now()
},
});
module.exports = mongoose.model('DHCustomerinvoice', DHCustomerinvoiceSchema);
COLLECTION EXAMPLE
{
"id": "5ef6*****",
"Saledetail": [
{
"id": "5ebf*****",
"quantity": 9,
"price": 2000,
"totalline": 18000
}
],
"datesale": "1593129600000",
"grandtotal": 18000,
"user": "5eb9ab******",
"customer": {
"name": "isabella"
},
"state": "PAID"
},
RESOLVER:
mostSellingProducts: async (_,{},ctx)=>{
const Products = await invoice.aggregate([
{ $unwind: "$Saledetail" },
{ $match: { "state" : 'PAID'}},
{ $group: {
_id : "$Saledetail.id",
total: { $sum: '$Saledetail.totalline' }
}},
{
$lookup: {
from: 'dhproducts',
localField: '_id',
foreignField: "_id",
as: "producto"
}
},
{
$limit: 4
},
{
$sort : {total: -1}
}
]);
console.log(Products);
return Products;
},
I have used many methods that actually did not give me this result, but nevertheless I have achieved a positive result in terms of finding my best clients who actually develop it with aggregate, match and group also apply sort and limit ...
but with this example I have not been able to achieve success, and I imagine that it is because the architecture of the collection is distinguished due to the arrangement of the purchase detail
I don't have enough reputation to comment on your question. So I am sharing this as an answer.
I think you can use $elemMatch to search for the item in an array.
const Productos = await Factura.aggregate([{ detlle: { $elemMatch: { $gte: 80, $lt: 85 } } }])
For more detailed info elemMatch
below the answer to my question
mostSellingProducts: async (_,{},ctx)=>{
const Products = await Invoice.aggregate([
{ $unwind: "$Saledetail" },
{ $match: { "state" : 'PAY'}},
{ $group: {
_id : { $toObjectId: "$Saledetail.id" },
total: { $sum: '$Saledetail.totalline' }
}},
{
$lookup: {
from: 'dhproducts',
localField: '_id',
foreignField: "_id",
as: "products"
}
},
{
$limit: 4
},
{
$sort : {total: -1}
}
]);
return Products;
},
I am currently learning aggregation and some related methods, after following mongoose and mongodb docs i tried it. but i am having problem.
Follow.aggregate([
{ $match: { user: mongoose.Types.ObjectId(userId) } },
{ $unwind: '$followers' },
{
$lookup: {
from: 'accounts',
localField: 'followers',
foreignField: '_id',
as: 'followers'
}
},
{ $project: { name: 1, photo: 1 } },
]).exec((err, followers) => {
if (err) throw err;
console.log(followers);
res.send(followers);
});
I want to get the followers of that userID and select the followers names and photo, but i am only getting the objectid of the matched document
[ { _id: 5bfe2c529419a560fb3e92eb } ]
expected output
[ { _id: 5bfe2c529419a560fb3e92eb , name: 'john doe", photo: 'cat.jpg'} ]
Follow Model
const FollowSchema = new Schema({
user: {
type: Schema.Types.ObjectId,
ref: 'Account',
required: true,
},
following: [{
type: Schema.Types.ObjectId,
ref: 'Account',
required: true,
}],
followers: [{
type: Schema.Types.ObjectId,
ref: 'Account',
required: true,
}],
});
When the $project stage is wrong you would get that result. Try removing it first and see the output. To me it seems you should have something like this there:
{ $project: { "followers.name": 1, "followers.photo": 1 } },
I have 2 schemas TravelRoute & Flights. I am trying to find the $min of Flight.fare.total_price and return that result with some details from TravelRoute which is ref-ed in the Flights schema. I am using Mongo 3.4.1 and Mongoose 4.8.5
const TravelRoute = new mongoose.Schema({
departureAirport: {
type: String,
required: true,
trim: true,
},
arrivalAirport: {
type: String,
required: true,
trim: true,
},
durationDays: {
type: Number
},
fromNow: {
type: Number
},
isActive: {
type: Boolean
},
class: {
type: String,
enum: ['economy', 'business', 'first', 'any']
}
}
const Flights = new mongoose.Schema({
route: {
type: mongoose.Schema.Types.ObjectId, ref: 'TravelRoute'
},
departure_date: {
type: Date
},
return_date: {
type: Date
},
fare: {
total_price: {
type: Number
}
}
}
I have the following code:
Flights.aggregate(
{$group: {
_id: {
route: '$route',
departure_date: '$departure_date',
return_date: '$return_date'
},
total_price: {$min: '$fare.total_price'}
}
},
{$lookup: {
from: 'TravelRoute',
localField: '_id.route',
foreignField: '_id',
as: 'routes'
}},
{$unwind: '$routes'},
{$project: {
'routes.departureAirport': 1,
'routes.destinationAirport': 1,
'departure_date': 1,
'return_date': 1,
'total_price': 1,
'_id': 1
}},
{$sort: {'total_price': 1}},
function(err, cheapFlights){
if (err) {
log.error(err)
return next(new errors.InvalidContentError(err.errors.name.message))
}
res.send(cheapFlights)
next()
})
The above returns an empty array [] when I use $unwind. When I comment out the $unwind stage, it returns the following:
[
{
"_id": {
"route": "58b30cac0efb1c7ebcd14e0a",
"departure_date": "2017-04-03T00:00:00.000Z",
"return_date": "2017-04-08T00:00:00.000Z"
},
"total_price": 385.6,
"routes": []
},
{
"_id": {
"route": "58ae47ddc30b175150d94eef",
"departure_date": "2017-04-03T00:00:00.000Z",
"return_date": "2017-04-10T00:00:00.000Z"
},
"total_price": 823.68,
"routes": []
}
...
I'm reasonably new to Mongo and Mongoose. I am confounded by the the fact that it returns "routes" even though I don't project that. And it doesn't return departure_date (etc) even though I ask for it? I am not sure I need $unwind as there will only be one TravelRoute per Flight.
Thanks...
Edit
Here was the final solution:
{$lookup: {
from: 'travelroutes', //<-- this is the collection name in the DB
localField: '_id.route',
foreignField: '_id',
as: 'routes'
}},
{$unwind: '$routes'},
{$project: {
departureAirport: '$routes.departureAirport',
arrivalAirport: '$routes.arrivalAirport',
departureDate: '$_id.departure_date',
returnDate: '$_id.return_date',
'total_price': 1,
'routeID': '$_id.route',
'_id': 0
}},
{$sort: {'total_price': 1}},