How to set ref to multiple models in Mongoose Schema definition? - mongodb

I need to create Model something like this:
const CommentSchema = new Schema(
{
userId: { type: Schema.Types.ObjectId, ref: 'User' },
text: { type: String, default: '' },
replyFor: { type: Schema.Types.ObjectId, ref: 'Post', default: null },
likes: { type: Number, default: 0 },
}
);
const CommentModel = model('Comment', CommentSchema);
module.exports = CommentModel;
The comment is comment for some post so in replyFor ref may be ref: 'Post' or it can be comment for other comment so ref: 'Comment'
So I need something like so:
const CommentSchema = new Schema(
{
userId: { type: Schema.Types.ObjectId, ref: 'User' },
text: { type: String, default: '' },
replyFor: { type: Schema.Types.ObjectId, ref: 'Comment Post', default: null },
likes: { type: Number, default: 0 },
}
);
So I need some how make some sort of generic reference.

Related

In Mongodb, how can i get posts by tags stored in user mode

post schema:
const BlogSchema = new mongoose.Schema(
{
title: {
type: String
},
content: {
type: String
},
author: {
type: mongoose.Schema.Types.ObjectId,
ref: Tags
},
content_type: {
type: mongoose.Schema.Types.ObjectId,
ref: Tags
},
valid_until: {
type: Date,
},
timestamp: {
type: Date,
default: Date.now
},
likes: { type: [String], default: [] },
},
);
user schema:
const mongoose = require('mongoose')
const UserProfileSchema = mongoose.Schema({
userid: {
type: String
},
firstname: {
type: String,
default: ''
},
tags: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'Tag'
}]
})
tag schema:
const TagSchema = new Schema({
name: {
type: String
},
type: {
type: Object,
},
color: {
type: String
},
timestamp: {
type: Date,
default: Date.now
},
});
this code is in post controller it will aggregate posts
const blogs = await Blog.aggregate([
{
$lookup: {
from: "tags",
localField: "author",
foreignField: "_id",
as: "blog_tags"
}
}])
What can i do to make it only get posts that are in user tags

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);
}
});

Collection referencing multiple collections

I want to have a collection with multiple fields referencing multiple collections, something like it:
var comboSchema = new Schema({
oneId: { type: Schema.Types.ObjectId, ref: "One" },
twoId: { type: Schema.Types.ObjectId, ref: "Two" },
threeId: { type: Schema.Types.ObjectId, ref: "Three" },
components: {
id: {type: Schema.Types.ObjectId, ref: "Component"},
amount: {type: Number}
}
}
I know I can use $lookup and aggregate to get data, but it looks like it works only on a single field in a collection?
Any help? Thank you! :-)
This is a model sample using the ref, the ref key in the object will take the name of the model in which you are referencing
const mongoose = require('mongoose');
const postSchema = mongoose.Schema({
text: {
type: String,
required: 1
},
mediatype: {
type: String,
required: 1
},
media: {
type: String,
required: true
},
user: {
type: mongoose.Schema.Types.ObjectId,
ref: 'user'
},
likes: {
type: [{
userid: {
type: mongoose.Schema.Types.ObjectId,
ref: 'user'
}
}]
},
comments: {
type: [{
userid: {
type: mongoose.Schema.Types.ObjectId,
ref: 'user'
},
comment: String
}]
},
}, {
timestamps: true
})
const Post = mongoose.model('post', postSchema)
module.exports = Post
so you can then populate it like Post.find().populate('user')

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?

Ordering two reference arrays together

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 }}});