I want to join/group differents collections in one

Ariel_P · 2022-05-30T21:55:57.396Z

yes, in Compass already at stage $group “subs” is an empty array

MaBeuLux88_xxx · 2022-05-30T21:56:53.559Z

Fix the earlier stage then. You can also disable some temporarily.

Ariel_P · 2022-05-30T21:58:08.189Z

The earlier stage is the $unwind you made…

MaBeuLux88_xxx · 2022-05-30T22:01:24.927Z

$unwind breaks arrays into multiple docs. If you have nothing after that stage, it means the array subscribers is empty in all the docs you have at this stage.
So something’s wrong above that.

MaBeuLux88_xxx · 2022-05-30T22:02:49.089Z

image1624×1003 129 KB

Ariel_P · 2022-05-30T22:03:51.681Z

My array subscribers is full of Object like this for example:

_id:5fc521659d588f6ab03661ff
uid:"FX8BBAH3VBH8T8051D"
reference:"FX8BBAH3VBH8T8051D"
total:0
setupFee:0
test:false
customerData:Object
sources:Array
subscription:5bf36db84bcbac7920daa39f
status:"active"
customer:5b8dd7bf26d681000f90bc20
startDate:2020-11-30T16:44:21.867+00:00
agenda:Array
customerToken:Array
executions:Array
created:2020-11-30T16:44:21.870+00:00
updated:2020-11-30T16:44:21.875+00:00
__v:0

(I took that directly from Compass)

MaBeuLux88_xxx · 2022-05-30T22:05:31.195Z

image1088×333 39.9 KB

That’s my stage right before $unwind.

Ariel_P · 2022-05-30T22:07:39.835Z

NOOOOO, you are the best, It was my fault…I didn’t put two $$ in my Compass, you made my day, sice friday I want to do this…

MaBeuLux88_xxx · 2022-05-30T22:08:58.558Z

Ariel_P · 2022-05-31T16:45:30.769Z

Hi, I think that the result is not what I need, can I make a new topic of this problem but with more details and examples?

MaBeuLux88_xxx · 2022-05-31T17:07:22.583Z

Of course! Ping me there with @MaBeuLux88.

Ariel_P · 2022-05-31T18:50:15.135Z

Before to star that, I want to show you this when I put .toArray() at the end of the aggregate on MONGOSH:

[
  {
    subs: [
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object],
      [Object], [Object], [Object], [Object]
    ]
  }
]

why the return is like a matrix of 4x12 dimension?

MaBeuLux88_xxx · 2022-05-31T21:44:41.329Z

It’s just display. Subs is just an array of 48 elements here. It’s just line wrapping to avoid going out of the screen.

Ariel_P · 2022-06-01T16:15:54.984Z

Can I show 'subs" in js o ts as a return of a method?

MaBeuLux88_xxx · 2022-06-01T16:23:12.358Z

Yes of course. Why would it be impossible?

Ariel_P · 2022-06-01T16:32:30.219Z

how can i do that? Because I don’t know how to do that because I have this:

class subscriberQuery{

  get subscriptions() {
    const MobbexDB = Mobbex.instance.storage.db;
    return MobbexDB.getModel("appsubscriptionsplans");
  }

  get subscribers() {
    const MobbexDB = Mobbex.instance.storage.db;
    return MobbexDB.getModel("appsubscriptionssubscribers");
  }

  public async getData(filters: any = {}, params: any = {}, batch: QueryBatchParams = { size: 500, skip: 0 }) {
    return this.getSubscribers(filters, params, batch);
  }

  public async getSubscribers(filters : any = {}, params : any = {}, batch: QueryBatchParams = {size : 500, skip : 0}) {
    return this.subscriptions
        .aggregate([
            {
              $match: {
                entity: params.entity, 
                status: 'active'
              }
            }, 
            {
              $lookup: {
                from: 'appsubscriptionssubscribers', 
                localField: '_id', 
                foreignField: 'subscription', 
                as: 'subscribers'
              }
            }, 
            {
              $match: {
                'subscribers.0': {
                  $exists: true
                }
              }
            },
            { $skip : batch.skip },
            { $limit : batch.size },  
            {
              $unwind: {
                path: '$subscribers'
              }
            }, 
            {
              $group: {
                _id: null, 
                subs: {
                  $push: '$$ROOT'
                }
              }
            },
            {
              $project: {
                _id: 0, 
                subs: 1
              }
            }
          ])
          .toArray();
  }
}

and I have to return in getData ‘subs’ and I don’t know how to extract that field…

MaBeuLux88_xxx · 2022-06-01T16:46:00.200Z

Checkout this blog post:

mongodb.com

Aggregation Framework with Node.js Tutorial | MongoDB

Discover how to analyze your data using MongoDB's Aggregation Framework and Node.js.

I think toArray() returns a Promise. Then you can just extract the value of subs from the doc once the Promise is resolved.

Not a JS expert here.

Ariel_P · 2022-06-01T17:32:32.818Z

how can I extract subs?..I am lost right now again, I created a variable call doc so I can save there await this.getSubscribers(filters, params, batch); but when I show that the result is this: [], any suggestion?

MaBeuLux88_xxx · 2022-06-01T20:18:25.927Z

const {MongoClient} = require('mongodb');

async function aggregation(client, pipeline) {
  return client.db("test").collection("coll").aggregate(pipeline).toArray();
}

async function main() {

  const uri = "mongodb://localhost/test";
  const client = new MongoClient(uri);
  const pipeline = [{
    "$match": {name: "Max"}
  }, {
    "$project": {_id: 0, my_array: 1}
  }];

  try {
    await client.connect();
    const coll = client.db("test").collection("coll");
    await coll.drop();
    const res = await coll.insertOne({name: "Max", my_array: [1, 2, 3]});
    console.log("Insert OK:", res);
    const docs = await aggregation(client, pipeline);
    const doc = docs[0];
    console.log("Entire doc:", doc);
    console.log("Just the array:", doc.my_array);
  } finally {
    await client.close();
  }
}

main().catch(console.error);

Result:

Insert OK: {
  acknowledged: true,
  insertedId: new ObjectId("6297c95481a3164ee6034d5b")
}
Entire doc: { my_array: [ 1, 2, 3 ] }
Just the array: [ 1, 2, 3 ]

system · 2022-06-06T20:18:59.113Z

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