How to set property of a model from a property of a `population` field in mongoose? - mongodb

I have a Post and its author property is set to User by using ref. Suppose there is a country field in User, how to make Post schema to have a country property as well which value is from User.country after population.
const Post = new Schema({
text: String,
author: {
type: ObjectId,
ref: 'User'
},
// How to set the virtual property country which is from User.country?
});
I know there is a Populate Virtuals in Mongoose, but it seems it just another way of populating, it won't pick up one of the properties, but the whole referenced record. Or maybe I get it wrong?
I know I can refer the country from Post.author.country, but I want a Post.country as well.
How to solve this?
Could I do this at the schema level?

If you use Populate Virtuals you can do the following :
var schemaOptions = {
toObject: {
virtuals: true
},
toJSON: {
virtuals: true
}
};
var PostSchema = new Schema({
text: String,
id: false,
author: {
type: Schema.Types.ObjectId,
ref: 'User'
}
}, schemaOptions);
PostSchema.virtual('country').get(function() {
return this.author.country;
});
Using :
Post.find({}).populate('author').exec(function(error, data) {
console.log(JSON.stringify(data));
});
it gives :
[{
"_id": "59d924346be5702d16322a67",
"text": "some text",
"author": {
"_id": "59d91f1a06ecf429c8aae221",
"country": "France",
"__v": 0
},
"__v": 0,
"country": "France"
}]
Check this gist for a full example

Related

Mongoose query not showing subdocument

I can't get mongoose to show subdocument when running find() while it displays perfectly well in mongodb shell.
Subdocument should be embedded based on my schema, not objectId referenced, so I shouldn't be running any black magic voodoo to get my data to show up.
const UserSchema = new mongoose.Schema({
username: String;
xp: Number;
//etc.
});
const RoomSchema = new mongoose.Schema({
timestamp: { type: Date, default: Date.now },
status: { type: String, enum: ["pending", "ongoing", "completed"]},
players: {
type: [{
points: { type: Number, default: 0 },
position: String,
user: UserSchema
}],
maxlength:2
}
});
After adding a new room with:
let room = new Room(coreObj);
room.players.push({
points: 0,
position: 'blue',
user: userObj //where userObj is a result of running findById on User model
});
It displays nicely in mongo shell, when running db.rooms.find({}).pretty() I can see that full document has been added. However, when running on mongoose model:
Room.find({}).exec((err,rooms)=>{
console.log(rooms[0].toJSON());
});
I don't see user subdocument, moreover I cannot see user field entirely! What seems to be the problem?
logged json from mongoose model:
{
"status": "pending",
"_id": "5cf5a25c050db208641a2076",
"timestamp": "2019-06-03T22:42:36.946Z",
"players": [
{
"points": 0,
"_id": "5cf5a25c050db208641a2077",
"position": "blue"
}
],
"__v": 0
}
json from mongo shell:
{
"_id" : ObjectId("5cf5a25c050db208641a2076"),
"status" : "pending",
"timestamp" : ISODate("2019-06-03T22:42:36.946Z"),
"players" : [
{
"points" : 0,
"_id" : ObjectId("5cf5a25c050db208641a2077"),
"position" : "blue",
"user" : {
"xp" : 0,
"_id" : ObjectId("5cf2da91a45db837b8061270"),
"username" : "bogdan_zvonko",
"__v" : 0
}
}
],
"__v" : 0
}
Keeping best practice in mind, I think it would be more appropriate to reference the UserSchema in the RoomSchema. Something like:
...
user: {
type: Schema.Types.ObjectId,
ref: 'UserSchema'
}
Then you would store the user._id in that field.
This way, if the user is modified, your RoomSchema is always referencing the correct information. You could then get the user using Mongoose's populate
I'm not entirely sure why you can't see the sub-sub-document, but this code example printed it correctly for me. Example was originally posted in https://mongoosejs.com/docs/subdocs.html but modified slightly to contain sub-sub-document so it looks similar to your code:
var grandChildSchema = new mongoose.Schema({ name: 'string' });
var childSchema = new mongoose.Schema({ name: 'string', grandChild: grandChildSchema });
var parentSchema = new mongoose.Schema({ children: [childSchema] });
var Parent = mongoose.model('Parent', parentSchema);
var parent = new Parent({
children: [
{ name: 'Matt', grandChild: {name: 'Matt Jr'} },
{ name: 'Sarah', grandChild: {name: 'Sarah Jr'} }
]
})
parent.save(function() {
Parent.find().exec(function(err, res) {
console.log(JSON.stringify(res[0]))
mongoose.connection.close()
})
});
Executing this code resulted in:
{
"_id": "5cf7096408b1f54151ef907c",
"children": [
{
"_id": "5cf7096408b1f54151ef907f",
"name": "Matt",
"grandChild": {
"_id": "5cf7096408b1f54151ef9080",
"name": "Matt Jr"
}
},
{
"_id": "5cf7096408b1f54151ef907d",
"name": "Sarah",
"grandChild": {
"_id": "5cf7096408b1f54151ef907e",
"name": "Sarah Jr"
}
}
],
"__v": 0
}
This was tested using Mongoose 5.5.12.
Note that I was using JSON.stringify() to print the document instead of using Mongoose's toJSON().
I just met a very similar problem, i think i got it.
the whole point is in model which you use:
const RoomSchema = new mongoose.Schema({
...
players: {
type: [{
...
user: UserSchema
...
but then you make
room.players.push({
points: 0,
position: 'blue',
user: userObj //where userObj is a result of running findById on User model
});
so you are missing the "type" subfield, so your doc is not compliant with your RoomSchema and mongoose do not show the parts which does not fit schema.

Prevent _id from being populated by just one schema

So I have the following schema:
var List = new Schema(
{
item_details_template: {
default: [
{
"title": "Name",
"content": "",
"hidden": false,
"order": 0,
"the_type": "text"
},
{
"title": "Price",
"content": "",
"hidden": false,
"order": 1,
"the_type": "text"
},
{
"title": "Company",
"content": "",
"hidden": false,
"order": 2,
"the_type": "text"
}
],
type: [Item_Detail]
}
}
)
However, I don't want ONLY this schema (subdocument) to not create _id fields. How do I do this? I know you can change the original schema itself, but it's being used by other Schemas, where I would like the _id to be populated.
To suppress _id on the item_detail_template, you need to restructure the way you create subdocument as follows
var mongoose = require("mongoose");
var subSchema = mongoose.Schema({
//your subschema content
},{ _id : false });
var schema = mongoose.Schema({
// schema content
subSchemaCollection : [subSchema] // item_details_template
});
var model = mongoose.model('tablename', schema);
If you want to suppress _id on the item_detail_template in the List schema only:
var List = new Schema(
{
item_details_template: {
_id:false, // should supress _id property
default: [
...
var widgetSchema = new Schema({ ... attributes ... }, { versionKey: false });

Mongodb pull from array attached to simple schema

I have the following collection attached to aldeed:simple schema
Posts = new Mongo.Collection("posts");
Posts.attachSchema(new SimpleSchema({
samplePost:{
type:String,
max:500
},
createdAt:{
type: Date,
autoValue: function(){
return new Date()
}
},
"comments.$.reply":{
type:String
},
"comments.$.commentId":{
type: String,
autoValue: function(){
var tempCommentId = new Meteor.Colletion.ObjectID();
return tempCommentId.str;
}
},
"comments.$.commentCreatedAt": {
type: Date,
optional: true,
autoValue: function(){
return new Date()
}
},
});
The actual document looks like the following:
{
"_id": "aaa",
"samplePost": "Hello world!",
"comments": [
{
"reply": "Goodbye",
"commentId": "bbb",
"createdAt": "2016-06-19T19:06:17.931Z"
},
{
"reply": "Good morning",
"commentId": "ccc"
"createdAt": "2016-06-19T19:05:17.931Z"
},
]
}
Now im trying to remove only the 2nd comment with commentId:"ccc" from the document with $pull
"click #delete-comment": function(event, template){
var tempCommentId = $(event.target).parent().find('#commentIdPass').text(); //commentId is collected from HTML view
Posts.update(
{_id: template.data._id}, //_id is collected from the url param
{$pull:{
comments: {
commentId: tempCommentId
}}
});
},
and this is not working. I have narrowed down the problem to
"comments.$.commentCreatedAt": {
type: Date,
optional: true,
autoValue: function(){
return new Date()
}
},
schema. If i remove this schema, i can delete the comment.
So, why is this causing a problem of pulling the whole comment item from the array. Any ideas? Any workarounds?
Try This Query:
db.getCollection('Mytest').update({"_id":"aaa"},{"$pull":{"comments":{"commentId":"ccc"}}});
Found the problem. As I have suspected attached schema was the culprit. I needed to set a conditional for inserting and updating a schema with autovalue method. The schema should look as following:
"comments.$.commentCreatedAt": {
type: Date,
autoValue: function () {
if (this.isInsert) {
return new Date;
}
}
},

How to correctly link collections in MongoDB/Mongoose

I am currently developing a Questionbank and I would like to link test results to user accounts. I am new to the noSQL database structure and I just wanted an opinion from the experts as to the best way to link the results to the user.
Should I have the userSchema to have a reference to a user specific test score collection? Or just link to keys in a global collection of test scores with "ref:"?
You should think data which your need as a JSON and other entities as a properties and property array.
I hope this code will help you:
Question:
{
"title" : "It's a title of question",
"otherProperty" : Boolean,
"created_by: {
"name": "User Who Created Question",
"otherProperty":0
},
"answers": [
{"text":"Answer content",
"created_by": {
"name":"User Who Answered Question
},
"otherProperty":False
},
{"text":"Answer content",
"created_by": {
"name":"User Who Answered Question
},
"otherProperty":False
},
{"text":"Answer content",
"created_by": {
"name":"User Who Answered Question
},
"otherProperty":False
}
]
}
In side of code you should read mongoose docs but you will use Ref key usually. Like this:
var Schema = mongoose.Schema;
var QuestionSchema = new Schema({
title: {
type: String,
required: true
},
answers: [{
type: Schema.Types.ObjectId,
ref: 'Answer'
}]
})
var Answer = new Schema({
text: {
type: String,
required: true
},
created_by: {
type: Schema.Types.ObjectId,
ref: 'User'
}
})
I hope it will help you.
UPDATE: I just updated sample code for first example.

auto increment ids in mongoose

How do I have autoincrement ids in mongoose? I want my ids to start like 1, 2, 3, 4, not the weird id numbers mongodb creates for you?
Here's my schema:
var PortfolioSchema = mongoose.Schema({
url: String,
createTime: { type: Date, default: Date.now },
updateTime: { type: Date, default: Date.now },
user: {type: Schema.Types.ObjectId, ref: 'User'}
});
Use mongoose-auto-increment:
https://github.com/codetunnel/mongoose-auto-increment
var mongoose = require('mongoose');
var autoIncrement = require('mongoose-auto-increment');
var connection = ....;
autoIncrement.initialize(connection);
var PortfolioSchema = new mongoose.Schema({
url: String,
createTime: { type: Date, default: Date.now },
updateTime: { type: Date, default: Date.now },
user: {type: Schema.Types.ObjectId, ref: 'User'}
});
//Auto-increment
PortfolioSchema.plugin(autoIncrement.plugin, { model: 'Portfolio' });
module.exports = mongoose.model('Portfolio', PortfolioSchema);
Or if you prefer to use an additional field instead of overriding _id, just add the field and list it in the auto-increment initialization:
var PortfolioSchema = new mongoose.Schema({
portfolioId: {type: Number, required: true},
url: String,
createTime: { type: Date, default: Date.now },
updateTime: { type: Date, default: Date.now },
user: {type: Schema.Types.ObjectId, ref: 'User'}
});
//Auto-increment
PortfolioSchema.plugin(autoIncrement.plugin, { model: 'Portfolio', field: 'portfolioId' });
If you want to have a incrementing numeric value in _id then the basic process is you are going to need something to return that value from a store somewhere. One way to do this is use MongoDB itself to store data that holds the counters for the _id values for each collection, which is described within the manual itself under Create and Auto-Incrementing Sequence Field.
Then as you create each new item, you use the implemented function to get that "counter" value, and use it as the _id in your document.
When overriding the default behavior here, mongoose requires that you both specify the _id and it's type explicitly with something like _id: Number and also that you tell it to no longer automatically try to supply an ObjectId type with { "_id": false } as an option on the schema.
Here's a working example in practice:
var async = require('async'),
mongoose = require('mongoose'),
Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/test');
var counterSchema = new Schema({
"_id": String,
"counter": { "type": Number, "default": 1 }
},{ "_id": false });
counterSchema.statics.getNewId = function(key,callback) {
return this.findByIdAndUpdate(key,
{ "$inc": { "counter": 1 } },
{ "upsert": true, "new": true },
callback
);
};
var sampleSchema = new Schema({
"_id": Number,
"name": String
},{ "_id": false });
var Counter = mongoose.model( 'Counter', counterSchema ),
ModelA = mongoose.model( 'ModelA', sampleSchema ),
ModelB = mongoose.model( 'ModelB', sampleSchema );
async.series(
[
function(callback) {
async.each([Counter,ModelA,ModelB],function(model,callback) {
model.remove({},callback);
},callback);
},
function(callback) {
async.eachSeries(
[
{ "model": "ModelA", "name": "bill" },
{ "model": "ModelB", "name": "apple" },
{ "model": "ModelA", "name": "ted" },
{ "model": "ModelB", "name": "oranage" }
],
function(item,callback) {
async.waterfall(
[
function(callback) {
Counter.getNewId(item.model,callback);
},
function(counter,callback) {
mongoose.model(item.model).findByIdAndUpdate(
counter.counter,
{ "$set": { "name": item.name } },
{ "upsert": true, "new": true },
function(err,doc) {
console.log(doc);
callback(err);
}
);
}
],
callback
);
},
callback
);
},
function(callback) {
Counter.find().exec(function(err,result) {
console.log(result);
callback(err);
});
}
],
function(err) {
if (err) throw err;
mongoose.disconnect();
}
);
For convience this implements a static method on the model as .getNewId() which just descriptively wraps the main function used in .findByIdAndUpdate(). This is a form of .findAndModify() as mentioned in the manual page section.
The purpose of this is that it is going to look up a specific "key" ( actually again the _id ) in the Counter model collection and perform an operation to both "increment" the counter value for that key and return the modified document. This is also aided with the "upsert" option, since if no document yet exists for the requested "key", then it will be created, otherwise the value will be incremented via $inc, and it always is so the default will be 1.
The example here shows that two counters are being maintained independently:
{ _id: 1, name: 'bill', __v: 0 }
{ _id: 1, name: 'apple', __v: 0 }
{ _id: 2, name: 'ted', __v: 0 }
{ _id: 2, name: 'oranage', __v: 0 }
[ { _id: 'ModelA', __v: 0, counter: 2 },
{ _id: 'ModelB', __v: 0, counter: 2 } ]
First listing out each document as it is created and then displaying the end state of the "counters" collection which holds the last used values for each key that was requested.
Also note those "weird numbers" serves a specific purpose of always being guranteed to be unique and also always increasing in order. And note that they do so without requiring another trip to the database in order to safely store and use an incremented number. So that should be well worth considering.