I am using mongoose 4.6.3.
I have the following schema :
var mongoose = require('mongoose');
var User = require('./User');
var TicketSchema = new mongoose.Schema({
user : { type: mongoose.Schema.Types.ObjectId, ref: 'User', required: true },
},
{
timestamps: true
});
var DrawSchema = new mongoose.Schema({
...
max_ticket_per_user : { type : Number, required: true },
tickets: [TicketSchema]
});
module.exports = mongoose.model('Draw', DrawSchema);
How can I count the embedded documents of a certain User ObjectId(user field in TicketSchema) in a Draw's tickets(tickets field in DrawSchema) ?
I want to count the tickets of a user for a single draw.
Would it be better to change my schema design ?
Thanks
You can use the aggregation framework taking advantage of the $filter and $size operators to get the filtered array with elements that match the user id and its size respectively which will subsequently give you the count.
For an single draw, consider adding a $match pipeline operator as your initial step with the _id query to filter the documents in the collection.
Consider running the following aggregation pipeline to get the desired result:
Draw.aggregate([
{ "$match": { "_id": drawId } },
{
"$project": {
"ticketsCount": {
"$size": {
"$filter": {
"input": "$tickets",
"as": "item",
"cond": { "$eq": [ "$$item.user", userId ] }
}
}
}
}
}
]).exec(function(err, result) {
console.log(result);
});
You can pass the .count() deep parameters like any other query object:
Draw.count({'tickets.user._id' : userId}, console.log);
Make sure the userId variable is an ObjectId. If it's a string, do this:
const ObjectId = require('mongoose').Types.ObjectId;
let userId = new ObjectId(incomingStringId);
Related
I have these two models:
User.js
const UserSchema = new Schema({
profile: {
type: Schema.Types.ObjectId,
ref: "profiles",
},
following: [
{
type: Schema.Types.ObjectId,
ref: "users",
},
],
});
module.exports = User = mongoose.model("users", UserSchema);
Profile.js
const ProfileSchema = new Schema({
videoURL: {
type: String,
},
});
module.exports = Profile = mongoose.model("profiles", ProfileSchema);
Here's an example of a User document:
{
"following": [
{
"profile":{
"videoURL":"video_url_1"
}
},
{
"profile":{
"videoURL":"video_url_2"
}
},
{
"profile":{}
},
{
"profile":{
"videoURL":"video_url_3"
}
},
{
"profile":{
"videoURL":"video_url_4"
}
},
{
"profile":{
"videoURL":"video_url_5"
}
},
{
"profile":{}
},
{
"profile":{
"videoURL":"video_url_6"
}
}
]
}
I am trying to implement an infinite scroll of the videos of the users followed by the connected user.
This means, I will have to filter user.following.profile.videoURL
WHERE videoURL exists
Suppose, I will be loading two videos, by two videos:
Response 1: ["video_url_1","video_url_2"]
Response 2: ["video_url_3","video_url_4"]
Response 3: ["video_url_5","video_url_6"]
Usually, infinite scroll is easy because all I have to load the documents 2 by 2 by order of storage without filtering on any field.
Example: Displaying the followed users two by two in an infinite scroll
User.findById(user_id).populate({
path: "following",
options: {
skip: 2 * page,
limit: 2,
},
});
But, now I have to perform filtering on each followed_user.profile.video, and return two by two. And I don't see how I can perform BOTH the filtering and the infinite scroll at the same time.
NOTE: According to the documentation:
In general, there is no way to make populate() filter stories based on properties of the story's author. For example, the below query won't return any results, even though author is populated.
const story = await Story.
findOne({ 'author.name': 'Ian Fleming' }).
populate('author').
exec();
story; // null
So I suppose, there is no way for me to use populate to filter based user.followers, based on each user.follower.profile.videoURL
I am not sure it is possible with populate method, but you can try aggregation pipeline,
$match user_id condition
$lookup with aggregation pipeline in users collection for following
$match following id condition
$lookup with profile for following.profile
$match videoURL should exists
$project to show profile field and get first element using $arrayElemAt
$slice to do pagination in following
let page = 0;
let limit = 2;
let skip = limit * page;
User.aggregate([
{ $match: { _id: mongoose.Types.ObjectId(user_id) } },
{
$lookup: {
from: "users",
let: { following: "$following" },
pipeline: [
{ $match: { $expr: { $in: ["$_id", "$$following"] } } },
{
$lookup: {
from: "profiles",
localField: "profile",
foreignField: "_id",
as: "profile"
}
},
{ $match: { "profile.videoURL": { $exists: true } } },
{
$project: {
profile: { $arrayElemAt: ["$profile", 0] }
}
}
],
as: "following"
}
},
{
$addFields: {
following: {
$slice: ["$following", skip, limit]
}
}
}
])
Playground
Suggestion:
You can improve your schema design,
removing profile schema and add profile object in users collection, so you can achieve easily your requirement using populate method,
put match condition in following populate for videoURL exists
const UserSchema = new Schema({
profile: {
type: {
videoURL: {
type: String
}
}
},
following: [
{
type: Schema.Types.ObjectId,
ref: "users"
}
]
});
module.exports = User = mongoose.model("users", UserSchema);
User.findById(user_id).populate({
path: "following",
match: {
"profile.videoURL": { $ne: null }
},
options: {
skip: 2 * page,
limit: 2,
}
});
So what you want is table with infinite scroll and:
You can opt given ways to approach your problem :
Load data (first page) into grid.
Set filter on a col.
Load data again, this time using the filter.
I can't push items into MongoDB array every time that i try to push a new element it creates an empty object and i cant figure out why,
I already used the
Collection.Array.push({element})&
Collection.save()
but i cant figure out a solution
This is My Schema
const Schema = mongoose.Schema;
var ParticipantSchema = new Schema({
nom:{Type:String},
prenom:{Type:String},
email:{Type:String}
})
var CompetitionSchema = new Schema({
nom:String,
date:Date,
place:String,
participant :[ParticipantSchema]
})
module.exports = mongoose.model("Competition",CompetitionSchema);
This is my funtion
exports.addParticipant=function(req,res){
var newParticipant={
"nom":req.body.nom,
"prenom":req.body.prenom,
"email":req.body.email
}
Competition.updateOne(
{ _id:req.body.id},
{ $push: { participant: newParticipant } },
(err,done)=>{
return res.json(done)
}
);
}
the result is always an empty object like below
{
"_id": "5ded0eeb85daa100dc5e57bf",
"nom": "Final",
"date": "2019-01-01T23:00:00.000Z",
"place": "Sousse",
"participant": [
{
"_id": "5ded0eeb85daa100dc5e57c0"
},
{
"_id": "5dee3c1b08474e27ac70672e"
}
],
"__v": 0
}
There is no problem in your code, the only problem is that in schema definition you have Type, but it must be type.
If you update your ParticipantSchema like this, it will work:
var ParticipantSchema = new Schema({
nom: { type: String },
prenom: { type: String },
email: { type: String }
});
You are using another Schema in the Array. This results in so-called subdocuments (https://mongoosejs.com/docs/subdocs.html). Mongoose does not populate subdocuments by default. So all you see is just the _id. You can use the populate method to see all subdocuments in detail. ( https://mongoosejs.com/docs/populate.html ) .
Example :
Competition.
find({}).
populate('participant').
exec(function (err, comps) {
//
});
You can either use populate on the Model or on the Document. For populating a document, take a look at https://mongoosejs.com/docs/api.html#document_Document-populate . There is also a auto-populate plugin available via npm but in most cases it's not necessary : https://www.npmjs.com/package/mongoose-autopopulate .
I have a voting app and I have a mongoose scheme as follows:
var optionSchema=new mongoose.Schema({
option:{type:String,required:true},
count:{type:Number,required:true}
});
var pollSchema = new mongoose.Schema({
creator:{type:String,required:true},
title:{type:String,required:true},
options:[optionSchema]
});
I am trying to figure out if I can pull the top X documents by the aggregate count of all the options for each document in node
Try something like this:
db.polls.aggregate([
{
$project: {
totalOptionCount: { $sum: "$options.count"}
},
},
{ $sort : { totalOptionCount : 1 }},
{ $limit : 5 }
])
I want to get all detail of particular record by reference id collection.
{
"_id" : ObjectId("586c8bf63ef8480af89e94ca"),
"createdDate" : ISODate("2017-01-04T05:45:26.945Z"),
"branch" : {
"$ref" : "branchmst",
"$id" : "5864ac80fa769f09a4881791",
"$db" : "eviral"
},
"__v" : 0
}
This is my collection record. I need to all detail from "branchmst" collection where "_id" is "5864ac80fa769f09a4881791".
Your collection is an example of using manual references i.e. including one document's _id field in another document DBref. Mongoose can then issue a second query to resolve the referenced fields as needed.
The second query would be to use the aggregate method which has the $lookup operator that will perform a left outer join to "branchmst" collection in the same database to filter in documents from the "joined" collection for processing:
MyModel.aggregate([
{ "$match": { "branch": "5864ac80fa769f09a4881791" } },
{
"$lookup": {
"from": "branchmst",
"localField": "branch",
"foreignField": "_id",
"as": "branchmst"
}
},
{ "$unwind": "$branchmst" }
])
You can also use the populate() function in Mongoose given you have explicitly defined the refs in your Model definition i.e.
var mongoose = require('mongoose');
var ObjectId = mongoose.Schema.Types.ObjectId;
// define the main schema
var mySchema = mongoose.Schema({
createdDate: { type: Date, default: Date.now },
branch: { type: ObjectId, ref: 'Branch' }
})
// define the branch schema
var branchSchema = mongoose.Schema({
name: String,
address: String
})
// compile the models
var MyModel = mongoose.model('MyModel', mySchema),
Branch = mongoose.model('Branch', branchSchema);
// populate query
MyModel.find({ "branch": "5864ac80fa769f09a4881791" })
.populate('branch')
.exec(function (err, docs) {
//console.log(docs[0].branch.name);
console.log(docs);
});
provided you saved your branch.$id as type Schema Object.
yourRecord.find({}).populate(branch.$id).exec(function(err, data){
console.log(data)
})
Schema of group and member are as below:
var group=new Schema({
group_id:Number,
group_name:String,
members:[member]
});
var member=new Schema({
member_id:number,
name:String,
});
Sample document after inserting some record in group collection
[{
_id:55ff7fca8d3f6607114dc57d
group_id:1001,
group_name:"tango mike",
members:[
{
_id:44ff7fca8d3f6607114dc21c
member_id:2001,
member_name:"Bob martin" ,
address:String,
sex:String
},
{
_id:22ff7fca8d3f6607114dc22d
member_id:2002,
member_name:"Marry",
address:String,
sex:String
},
{
_id:44ff7fca8d3f6607114dc23e
member_id:2003,
member_name:"Alice" ,
address:String,
sex:String
}
]
}]
My problem:
I am trying to update record of individual group member(element of subdocument members). While updating I have follwing data group: _id, group_id, members:_id and newdata. I am trying like this; but it is not working
var newData={
member_name:"Alice goda" ,
address:"xyz",
sex:"F"
}
groupModel.findOne({"_id":"55fdbaa7457aa1b9bd7f7cf7","group_id":1001},'members -_id',function(err,groupMembers){
if(err)
{
res.json({
"isError":true,
"error":{
"status":1042,
"message":err
}
});
}
else
{
var mem=groupMembers.id("44ff7fca8d3f6607114dc23e");
mem.member_name=newData.member_name;
mem.address=newData.address;
mem.sex=newData.sex;
mem.save(function(err,data){
if(!err)
//sucessfull updated
});
res.json(groupDetails);
}
});
As I understand from your question details, you would like to update one object from the members array, in accordance with the criteria that you specify.
Thus, in order to accurately run the update query for your use case, you could run the following update operation against your collection:
db.collection.update({ _id: "55ff7fca8d3f6607114dc57d",
group_id:1001,
members: {
$elemMatch: { _id: "44ff7fca8d3f6607114dc23e" }
}
},
{ $set: {
"members.$.member_name": "Alice goda",
"members.$.address": "xyz",
"members.$.sex": "F"
}});
Still, be aware that the $ positional operator only updates the first array item that matches your query.
Unfortunately, there is no possibility of updating all the array elements that match your criteria in a single operation. As you can see on MongoDB Jira, the aforementioned feature is one of the most requested functionality, but it has not yet been directly implemented in MongoDB.