How to compare _id value of Models made using Mongoose? - node.js

I have the following two schemas of User and Critique and I've got the data persisted in MongoDB database:
var userSchema = mongoose.Schema({
critiques: [{ type: Schema.ObjectId, ref: 'Critique' }],
});
var User = mongoose.model("User", userSchema);
var critiqueSchema = mongoose.Schema({
author: {type: String, default: ''},
date: { type: Date, default: Date.now },
comment: { type: String, default: '' },
stars: { type: Number, default: 0 },
_user: { type: Schema.ObjectId, ref: 'User' }
});
var Critique = mongoose.model("Critique", critiqueSchema);
user.critiques[0]._id.equals(critique._id) is giving me undefined is not a function.
How to compare _id value of a User instance with the Critique instance?

The critiques field of your user object directly contains an array of ObjectIds, so it would just be:
user.critiques[0].equals(critique._id)
user.critiques would only contain full Critique objects if you chained a .populate('critiques') call in the find where you obtained user.

Related

How to create a dynamic nested mongoose document with the same schema on multiple levels

Before everyone tells me I can't call a const before initializing, I do know that.
But I think this is the simplest way to render the concept I have in mind, (where any subdocument within the replies array also has the same schema as the parent, and documents within the replies array of those subdocuments also having the same schema). I would really appreciate anyone's input.
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
var commentSchema = new mongoose.Schema({
content: String,
createdAt: {
type: Date,
default: Date.now
},
score: {
type: Number,
default: 1
},
username: {
type: String,
lowercase: true
},
parent: {
type: Schema.Types.ObjectId,
ref: 'comment'
},
replyingTo: String,
replies: [commentSchema]
});
module.exports = mongoose.model("comment", commentSchema);
Since a const can't be called before initialization, to fix this issue the parent schema should be called on the children array after initialization the code below:
commentSchema.add({ replies: [commentSchema] })
The final result should look like this:
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const commentSchema = new mongoose.Schema({
content: String,
createdAt: {
type: Date,
default: Date.now
},
score: {
type: Number,
default: 1
},
username: {
type: String,
lowercase: true
},
parent: {
type: Schema.Types.ObjectId,
ref: 'comment'
},
replyingTo: String,
});
commentSchema.add({ replies: [commentSchema] })

Mongoose not populating related array

I have followed the mongoose docs for populating related objects, everytime authSessions is empty. I can see in mongo sessions are being populated along with the related userId field. I have tried specifying ”path” and “model” options in the populate function as well but that didn’t work either. Anyone have any ideas?
//Session.js
const SessionSchema = new mongoose.Schema({
_id: Schema.Types.ObjectId,
sessionId: { type: String, index: true },
createdDate: { type: Date, default: Date.now },
revoked: Boolean,
revokedAt: Date,
userId: {type: Schema.Types.ObjectId, ref: 'User', index: true}
})
module.exports = mongoose.models.Session || mongoose.model('Session', SessionSchema);
//User.js
const UserSchema = new mongoose.Schema({
_id: Schema.Types.ObjectId,
username: { type: String, index: true },
email: { type: String, index: true },
password: String,
registrationDate: { type: Date, default: Date.now },
authSessions: [{type: Schema.Types.ObjectId, ref: 'Session'}]
})
module.exports = mongoose.models.User || mongoose.model('User', UserSchema);
const user = await User.findById(session.userId).populate('authSessions').exec();
console.log(user) //authSessions is empty
{
_id: new ObjectId("62b6ea393e042868caa68c7d"),
username: 'asdfasdfasdf',
email: 'testaskldjflk#djlkajdf.com',
password: 'testaskldjflk#djlkajdf.com',
authSessions: [], //empty here always
registrationDate: 2022-06-25T10:58:01.709Z,
__v: 0
} ```
MongoDB, and by extension mongoose, doesn't automatically create relations for you.
If you create a Session document, you need to explicitly add it to a User document if you want populate to work:
// create a new session document and save it
const userSession = new Session(…);
await userSession.save();
// !! update the user document and save it
user.authSessions.push(userSession);
await user.save();

How to query and get documents from two collections on mongoose

I need to query documents from two collections together on mongoose.
I am familiar with SQL query and but not familiar with mongoDB.
I have two schema for Users, Messages like following.
Users
const UserSchema = new mongoose.Schema({
name: String,
email: {type: String, unique: true},
password: String,
avatar: {type: String, default: ""},
created_at: { type: Date, default: Date.now() }
});
module.exports = mongoose.model('User', UserSchema);
Messages
const MessageSchema = new mongoose.Schema({
message: { type: String, default: "" },
from: { type: String, default: "" },
to: { type: String: default: "" },
is_read: { type: Boolean, default: false },
channel: { type: String, default: ''},
created_at: { type: Date, required: true, default: Date.now }
});
module.exports = mongoose.model('Message', MessageSchema);
I need to get messages with "is_read" is "false".
I want to get "user name" and "avatar" together.
The "from" value of message should be matched with "_id" of User.
I think this post sums it up well: Mongoose - query to get data from multiple collections
Specifically the second upvoted answer mentions similarities between sql and mongodb, and goes on to explain how to link collections in mongoose queries.

How to remove left-over ObjectId?

The problem is:
I have a collection of photos schema and likes schema, and inside photos there is an array of like ObjectIds called likeArray which is used to populate data from likes colletion.
But when i delete a like from likes collection, the ObjectId of that like in the likeArray still exists.
I tried to find the index of like._id in the likeArray and use likeArray.splice(index, 1) but couldn't work.
Can someone know the solution?
Here's the photo schema:
var Photo = mongoose.model('Photo', new mongoose.Schema({
photo_url: String,
photo_description: String,
user:{
id: {
type: mongoose.Schema.Types.ObjectId,
ref: 'user'
},
username: String,
profile_photo: String
},
comments: [
{
type: mongoose.Schema.Types.ObjectId,
ref: 'comment'
}
],
likes: [
{
type: mongoose.Schema.Types.ObjectId,
ref: 'like'
}
],
created_at: {type: Date, default: Date.now}
}));
Here's the Like schema:
var Like = mongoose.model('Like', new mongoose.Schema({
user_id: {
type: mongoose.Schema.Types.ObjectId,
ref: 'user'
},
photo_id: {
type: mongoose.Schema.Types.ObjectId,
ref: 'photo'
},
created_at: {type: Date, default: Date.now}
}));
Instead of splice you can use $pull operator. Here's how it'd look in mongo shell.
db.likes.remove({_id: like_oid});
db.photos.update({likes: like_oid}, {$pull: {likes: like_oid}}, { multi: true });

Mongoose Populate Method is not populating value

I have two mongoose schema as following
var ServiceSubType = new Schema({
displaySubTypeName : String,
subTypeDescription : String,
status : { type: String, default: Constants.ACTIVE },
lastUpdatedOn : Date,
createdOn : { type: Date, default: Date.now }
} , { collection: 'SERVICE_SUB_TYPES' });
and
var ServiceType = new Schema({
displayName : String,
description : String,
status : { type: String, default: Constants.ACTIVE },
lastUpdatedOn : Date,
serviceSubTypeId : {type: Schema.Types.ObjectId, ref: 'ServiceSubType', index: true},
createdBy : { type: Schema.Types.ObjectId, ref: 'SystemUser', index: true },
createdOn : { type: Date, default: Date.now }
} , { collection: 'SERVICE_TYPES' });
I have populated Type Object as below
module.exports.addNewServiceType = function(serviceType_obj, callback) {
serviceType_obj.save(serviceType_obj,callback);
}
Now I am trying to populate ServiceSubType document and then at the same time trying to populate "serviceSubTypeId" of ServiceType object referenced to ServiceSubType created.
Here is my piece of code for the same purpose.
module.exports.addServiceSubType = function(serviceTypeObjId, serviceSubType_obj, callback) {
serviceSubType_obj.save(serviceSubType_obj, function (error, serviceSubType) {
});
serviceSchema.ServiceType.findById(serviceTypeObjId, function (err, serviceType) {
var opts = { path: 'serviceSubTypeId'};
serviceSchema.ServiceType.populate(serviceType, opts, function (err, user) {
console.log(serviceType);
});
}).exec(callback);
}
But it is not workign and not populating any value in Existing SubType object.
I admit my approach could be very wrong as I am very new in this technology. Appreciate any kind of help to run this piece of code as expected.
Thanks
Ajoy
I think your ref should be the same setting as the collection on the object
serviceSubTypeId : {
type: Schema.Types.ObjectId,
ref: 'SERVICE_SUB_TYPES', <==== your collection type goes here
index: true
},
Mongoose doesn't know anything about your JavaScript object types. Instead, it tracks things based on the collection name that you provide (or that it generates).
update based on comments below
I have some example code that I wrote a while back, and it looks like I'm letting Mongoose generate the collection name for me. However, I am supplying a name to the mogoose.model() call, when registering my type for a collection.
For example, I have a Post type and a User type. The Post contains an author which is a reference to the User.
It looks like this:
// post
// ----
var PostSchema = new mongoose.Schema({
date: {type: Date, required: true, default: Date.now},
title: {type: String, required: true},
content: {type: String, required: true},
author: {
type: SchemaTypes.ObjectId,
ref: "user"
},
comments: [CommentSchema]
});
var Post = mongoose.model("blog", PostSchema);
// user
// ----
var UserSchema = mongoose.Schema({
firstName: {type: String},
lastName: {type: String},
username: {type: String, required: true, index: {unique: true}},
email: {type: String, required: true},
password: {type: String, required: true},
url: {
type: mongoose.Schema.Types.ObjectId,
ref: "url"
}
});
User = mongoose.model("user", UserSchema);
In this example code, I'm setting the ref to "user" because I am registering my model as "user" down below, in the mongoose.model method call.
Are you registering your models using mongoose.model and supplying a name? if so, use that name.

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