Ordering two reference arrays together - mongodb

Suppose I have the following schemas:
var QuizSchema = new mongoose.Schema({
name: { type: String, required: true },
questions: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Question' }],
questionGroups: [{ type: mongoose.Schema.Types.ObjectId, ref: 'QuestionGroup' }]
});
var QuestionSchema = new mongoose.Schema({
number: { type: String, required: true }, // e.g. 1, a, i, anything
question: { type: String, required: true },
type: { type: String, enum: ['multiple choice', 'multiple select', 'short answer'] },
choices: [String],
answers: [String]
});
var QuestionGroupSchema = new mongoose.Schema({
number: { type: String, required: true }, // e.g. 1, a, i, anything
prompt: { type: String },
questions: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Question' }]
});
I am trying to design a way that will allow me to order questions and question groups together.
I was thinking maybe of adding a new field order
var QuizSchema = new mongoose.Schema({
// ...
order: [
{
type: { type: String, enum: ['Question', 'QuestionGroup'] },
id: mongoose.Schema.Types.ObjectId // reference
}
]
});
such that in the database, the field would contain something such as
[
{ type: 'Question', id: ObjectId('57867a34567g67790') },
{ type: 'Question', id: ObjectId('57867a34567g67765') },
{ type: 'QuestionGroup', id: ObjectId('69864b64765y45645') },
{ type: 'Question', id: ObjectId('57867a34567g67770') },
{ type: 'QuestionGroup', id: ObjectId('69864b64767y45647') }
]
This may mean that I would need to "populate" the ordered list of questions and question groups as
quiz.populate('questions questionGroups').exec(function (err, quiz) {
// sort questions and groups by the order
quiz.order = quiz.order.map(function (o) {
if (o.type === 'QuestionGroup') {
return quiz.questionGroups.id(o.id);
}
return quiz.questions.id(o.id);
});
});
So my question: is there a better way to design this?

Virtuals can come in handy here; without persisting order field in db and doing calculations on client each time:
var QuizSchema = new mongoose.Schema({
name: { type: String, required: true },
questions: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Question' }],
questionGroups: [{ type: mongoose.Schema.Types.ObjectId, ref: 'QuestionGroup' }]
},
{
toObject: {
virtuals: true
},
toJSON: {
virtuals: true
}
}
);
QuizSchema
.virtual('order')
.get(function() {
return this.questions.concat(this.questionGroups); //questions followed by questionGroups
});
Sort on createdAt is of course optional, but for that you need to have this field in Question and QuestionGroup:
Quiz.find({}, function (err, quiz) {
//...
})
.populate({path : 'questions', options: {sort: { 'createdAt': 1 }}})
.populate({path : 'questionGroups', options: {sort: { 'createdAt': 1 }}});

Related

How to develop nested condition query in mongoDB

I am pretty new to mongoDb and want to apply nested query.
I have a business schema like this:
const businessSchema = new mongoose.Schema(
{
name: {
type: String,
required: true,
},
businessType: {
type: Schema.Types.ObjectId,
ref: "businessCategory",
required: true,
},
email: {
type: String,
required: true,
},
password: {
type: String,
required: true,
select: false,
},
review: {
type: [reviewSchema],
},
isDeleted: {
type: Boolean,
default: false,
},
},
{ timestamps: true }
);
Business has a review where user can do the review and reviewSchema is
const reviewSchema = new mongoose.Schema(
{
user: {
type: Schema.Types.ObjectId,
ref: "users",
required: true,
},
rating: {
type: Number,
enum: [1, 2, 3, 4, 5],
},
reviewArray: {
type: [singleReviewSchema],
},
},
{ timestamps: true }
);
One user can do many reviews, and it has reviewArray.
ReviewArray schema is
const singleReviewSchema = new mongoose.Schema(
{
title: {
type: String,
},
description: {
type: String,
},
isDeleted: {
type: Boolean,
default: false,
},
},
{ timestamps: true }
);
How to fetch the business with a condition business: isDeleted:false and its reviews with singleReviewSchema: isDeleted:false
I dont know your model names, so please replace path with correct names
but it might look like:
businnesModel.find({isDeleted: false})
.populate({
path: 'reviewModelName',
model: 'review',
populate: {
path: 'reviewArray',
model: 'singleReviewModelName',
match: {
isDeleted : false
}
}
})
It should provide you array of businessModel documents - even when their singleReviews array will be empty (because all of reviews are deleted, or there was zero reviews). So you have to filter it out in JS.
To avoid filtering in JS, and to do it a bit more efficient way for mongodb, you can go with aggregate instead.

Is it possible to have two types of objects in an array of mongoose schema

I am building an e-commerce application and this is my orders schema.
const mongoose = require("mongoose");
const orderSchema = new mongoose.Schema({
buyer: {
type: mongoose.Schema.Types.ObjectId,
ref: "buyer",
required: true
},
items: [{
item: {
type: mongoose.Schema.Types.ObjectId,
ref: "item",
},
quantity: {
type: Number,
default: 1
}}
],
seller: {
type: mongoose.Schema.Types.ObjectId,
ref: "seller",
required: true
},
location: {
type: {
type: "String",
enum:['Point']
},
coordinates: {
type: [Number],
index: '2dsphere'
}
},
sendAt:{
type: Date,
default: Date.now
}
});
const orderModel = mongoose.model("orders", orderSchema);
module.exports = orderModel;
I want to have an array having item-reference-id and quantity.
But with the above schema when i enter data, each item is acting as an another sub-document and having _id. Query response image.
I have found solution:
order: [
{
_id: false,
item: {
type: mongoose.Schema.Types.ObjectId,
ref: "items",
required: true,
},
quantity: { type: Number },
},
],
_id: false will stop the subdocument from creating another id for the subdocument.

find one with multiple conditions mongoose mongodb

I am trying to obtain data from mongodb. This is the scenario. Each user has a following property(array) that takes an array of users id.
The user model is as below
const userSchema = new mongoose.Schema({
name: {
type: String,
required: true,
},
email: {
type: String,
required: true,
},
password: {
type: String,
required: true,
},
followers: [{ type: mongoose.Types.ObjectId, ref: "user" }],
following: [{ type: mongoose.Types.ObjectId, ref: "user" }],
});
in simple terms. I need to use two conditions where postedBy: { $in: req.user.following }, or postedBy:req.user._id
const postSchema = new mongoose.Schema({
title: {
type: String,
required: true,
},
body: {
type: String,
required: true,
},
photo: {
type: String,
required: true,
},
likes: [{ type: mongoose.Schema.ObjectId, ref: "user" }],
comments: [
{
text: String,
postedBy: { type: mongoose.Schema.Types.ObjectId, ref: "user" },
},
],
postedBy: {
type: mongoose.Schema.Types.ObjectId,
ref: "user",
},
});
I have not figured out the second condition to add in the code below.
router.get("/getSubPost", requireLogin, async (req, res) => {
try {
const result = await Post.find({
postedBy: { $in: req.user.following },
})
.populate("postedBy", "-password")
.populate("comments.postedBy", "_id name");
res.json({ result });
} catch (error) {
console.log(error);
}
});

Associate one schema with another

I have my user schema:
const userSchema = new Schema({
name: { type: String, required: true },
email: { type: String, required: true },
password: { type: String, required: true },
date: { type: Date, default: Date.now },
active: { type: Boolean, default: false }
});
I want to create a leave status schema. Data will be given by only one user about all leave status. I want to associate each one of the leave status to there respective user schema id. I tried leave status schema as the following:
const leaveSchema = new Schema({
leave: [
{
email: { type: String, required: true },
month: { type: String, required: true },
year: { type: Number, required: true },
earnedleave: { type: Number },
sickleave: { type: Number },
festivalleave: { type: Number },
compoff: { type: Number }
}
]
});
How can i associate my emailid with userschema. Can it be possible? If so, how can i tweak it?
We don't need to associate the schema to get leave based on user, You can use aggregation for that,
db.user.aggregate([
...
{$lookup: {from: "leave", localField: "email", foreignField: "leave.email", as: "leaves"}},
...
]);
Still, If you like to associate two collection, You have to use ref using ObjectId
const leaveSchema = new Schema({
leave: [
{
user: { type: Schema.Types.ObjectId, ref: 'user' }, //Your model name as reference
email: { type: String, required: true },
month: { type: String, required: true },
year: { type: Number, required: true },
earnedleave: { type: Number },
sickleave: { type: Number },
festivalleave: { type: Number },
compoff: { type: Number }
}
]
});

Mongoose populate nested not working

I have this user model:
const userSchema = new mongoose.Schema({
...,
instances: {
type: Array,
default: [{
role: 'user'
}],
role: {
type: String,
enum: ['admin', 'user']
},
company: {
type: mongoose.Schema.ObjectId,
ref: 'Company'
},
},
},
{
timestamps: true
}
);
And company model:
const companySchema = new mongoose.Schema({
name: {
type: String,
required: true
},
logo: {
type: mongoose.Schema.ObjectId,
ref: 'File',
required: true
}
}, { timestamps: true });
And this pre find method:
userSchema.pre('findOne', function () {
this.populate({
path: 'instances.company',
populate: {
path: 'logo',
model: 'File'
}
});
});
I want to populate the instances companies on each find, and populate the logo of the company.
The thing is, that the company is populated, but not the logo path.
What am I doing wrong?