Problem on Sum of Mongo Aggregate (Big Number: 01 + 0.2)?

[robfallows]

It’s also worth pointing out that there is a limit on the value of the biggest integer JavaScript can accurately represent. That’s available in Number.MAX_SAFE_INTEGER and is 2⁵³-1 (9007199254740991).

[theara]

Thanks for all reply.
So the solution of this, we should use values in cents (as integer) by @serkandurusoy.
Eg: We will multiple all of value input with *100 (decimal number = 2 digits)

[theara]

Now I try to insert data with NumberDecimal (In Mongo Shell)

// Invoice
{
        _id: "1", 
        date: , 
        name: 'Maly', 
        amount: NumberDecimal('0.3')
}
-----------------
// Payment
{
   _id : "1",
   date :  ,
   paid : NumberDecimal('0.2'),
   invoiceId: "1"
},

{
   _id : "2",
   date : ,
   paid : NumberDecimal('0.1'),
   invoiceId: "1"
}

And then It work fine

db.invoices.aggregate([
   ............. // lookup to payment
    {
        $group:{
            _id: null,
            totalPaid: {$sum: "$paid"}
        }
    }
    ........ // project the balance field, and set status
 ])
----------------
// Result
{
	"_id" : null,
	"sum" : 0.3
}

[theara]

How us NumberDecimal in Meteor???

[robfallows]

Implement mongo 3.4 Decimal128 processing in meteor

Merged as the mongo-decimal package

meteor add mongo-decimal

Although the documentation is somewhat lacking

[theara]

Thanks again, Don’t have any document??
Could you example if you know?

[robfallows]

I have no examples, except the Tinytest code in the package.

[theara]

I check Decimal128on Node-Mongo driver.
But don’t understand how to use?

[theara]

Excuse me, Which one better Cents Number (as integer) VS Decimal Number???

[theara]

@robfallows, Which one better 1 VS 2:

1- Use mongo-decimal to store Mongo data as NumberDecimal

2- Use as normal Double, but we convert Double to Decimal by $toDecimal in Query Data
Ex:

Collection.aggregate([
  {
    addFields: { amountDbl: {$toDecimal: '$amount'}}
  },
  {
    $group:{_id: null, totalAmount: { $sum: "amountDbl"}}
  },
  {
    $project: {total: {$toDouble: '$total'}}
  }
])

[theara]

HI all, now I have problem when fetching data with Aggregate .
1- Meteor collection

let data = Collection.find, findOne 
---
doc.decimalField.toNumber() 
// Work fine with Decimal JS Method (Client/Server)

2- Use sakulstra:aggregate or Native node driver

let data = Collection.aggregate([.......]), Collection.rawCollection().aggregate([.....]) 
---
doc.decimalField.toNumber() 
// Don't work with Decimal JS Method (Client/Server)

Please help me…

[robfallows]

Collection.rawCollection().aggregate() returns a Promise.

If you are using it inside a Meteor Method, define your method as async and then await the result of the aggregation. You will also need to convert the aggregation cursor to an array. So something like this:

Meteor.methods({
  async doMyAggregation() {
    try {
      return await Collection.rawCollection().aggregate(aggPipeline).toArray();
    } catch(error) {
      throw new Meteor.Error(error.message);
    }
  },
});

[theara]

Yes I understand about this, but the problem is :
I can not convert Decimal field to Number by .toNumber() Decimal JS method on client/server side like .finde, findOne (Meteor collection)

[robfallows]

Ah, OK.

The Meteor package mongo-decimal just adds a few extra methods and properties to decimal.js. It also adds EJSON compatibility.

You should probably start by looking at the NPM package linked above. I suspect you’ll probably need to convert your MongoDB value to a Decimal before you’re able to manipulate it with toNumber().

const decNum = new Decimal(mongoDecimalValue);
console.log(decNum.toNumber());

I haven’t tried any of this!

[theara]

I tried, but get error

import { Decimal as DecJs } from 'decimal.js'

export const aggregateNumber = new ValidatedMethod({
  name: 'demo.aggregateNumber'
  validate: null,
  run() {
    if (Meteor.isServer) {
      let data = NumberVal.aggregate([
        {
          $limit: 1,
        },
      ])[0]
      data.valDecimal = new DecJs(data.valDecimal)

      return data
    }
  },
})

Error

Exception while invoking method 'demo.aggregateNumber' Error: [DecimalError] Invalid argument: 0.1
I20190523-19:42:22.037(7)?     at new Decimal (/Volumes/DATA/MeteorApp/meteor-element/node_modules/decimal.js/decimal.js:4302:15)
I20190523-19:42:22.037(7)?     at MethodInvocation.run (imports/api/demos/mongoDecimal.js:50:25)
I20190523-19:42:22.037(7)?     at ValidatedMethod._execute (packages/mdg:validated-method/validated-method.js:94:12)
I20190523-19:42:22.037(7)?     at MethodInvocation.demo.aggregateNumber (packages/mdg:validated-method/validated-method.js:57:23)
I20190523-19:42:22.038(7)?     at maybeAuditArgumentChecks (packages/ddp-server/livedata_server.js:1767:12)
I20190523-19:42:22.038(7)?     at DDP._CurrentMethodInvocation.withValue (packages/ddp-server/livedata_server.js:719:19)
I20190523-19:42:22.038(7)?     at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1304:12)
I20190523-19:42:22.038(7)?     at DDPServer._CurrentWriteFence.withValue (packages/ddp-server/livedata_server.js:717:46)
I20190523-19:42:22.038(7)?     at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1304:12)
I20190523-19:42:22.038(7)?     at Promise (packages/ddp-server/livedata_server.js:715:46)
I20190523-19:42:22.038(7)?     at new Promise (<anonymous>)
I20190523-19:42:22.038(7)?     at Session.method (packages/ddp-server/livedata_server.js:689:23)
I20190523-19:42:22.039(7)?     at packages/ddp-server/livedata_server.js:559:clock430:

[theara]

I tried to console valDeciaml

"valDecimal": { "_bsontype": "Decimal128", "bytes": { "0": 1, "1": 0, "2": 0, "3": 0, "4": 0, "5": 0, "6": 0, "7": 0, "8": 0, "9": 0, "10": 0, "11": 0, "12": 0, "13": 0, "14": 62, "15": 48 } } }

[robfallows]

import { Decimal as DecJs } from ‘decimal.js’

You are importing the NPM package, which does not have the methods and properties needed for returning serialised EJSON. You should import { Decimal } from 'meteor/mongo-decimal';.

However, the error at the top (Invalid argument: 0.1) suggests that there’s a problem with converting MongoDB’s representation.

You could try data.valDecimal = new Decimal(data.valDecimal.toString());

[theara]

Thanks, It work.
Why data.valDecimal is not Decimal JS?
If I use Collection.findOne({}), the valDecimal is Decimal js.
(don’t use data.valDecimal = new Decimal(data.valDecimal.toString()))

[robfallows]

Why data.valDecimal is not Decimal JS ?

The meteor/mongo package uses meteor/mongo-decimal to ensure the Decimal data identified with Meteor Mongo.Collections can be serialised with EJSON. The native MongoDB library doesn’t - you need to handle all this yourself.

[theara]

I will try the bast