How to convert Decimal128 value to Float value in Node.js / Mongoose?

Question

I got the following output from the Node.js backend server when I use the Orders.find() to find some documents from the MongoDB database.

{
    _id: new ObjectId('6672a038a102620d14a93cac'),
    userId: 6458,
    orderId: 106733,
    orderAmount: new Decimal128('134.25'),
    orderStatus: 100,
    orderDate: 2024-06-19T09:09:12.246Z,
    processed: false,
    __v: 0
  },

The Orders schema is as follows:

const OrderSchema = new mongoose.Schema({
  userId: {
    type: Number,
  },
  orderId: {
    type: Number,
  },
  orderAmount: {
    type: mongoose.Types.Decimal128,
  },
  orderStatus: {
    type: Number,
  },
  orderDate: {
    type: Date,
    default: Date.now,
  },
  processed: {
    type: Boolean,
    default: false,
  },
  
});

Appreciate your valuable help in converting the orderAmount from Decimal128 to a floating number.

My expected output is:

{
    _id: new ObjectId('6672a038a102620d14a93cac'),
    userId: 6458,
    orderId: 106733,
    orderAmount: 134.25,
    orderStatus: 100,
    orderDate: 2024-06-19T09:09:12.246Z,
    processed: false,
    __v: 0
  },

You can just apply the unary + to it, like +orderAmount, and you'll get a native JavaScript number type. Be aware that there can be loss of precision. — trincot
– trincot, Commented Jun 20, 2024 at 10:21
mongoplayground.net/p/2tFTFeyth-i not sure if there are better ways — cmgchess
– cmgchess, Commented Jun 20, 2024 at 10:30
@cmgchess, That was an awesome solution. It worked very well, Thank you! I believe you can put the same as a working solution so that I can mark it as a solution — DXB-DEV
– DXB-DEV, Commented Jun 20, 2024 at 11:35
@trincot, I didnot understand where and how should I apply the unary + operator... if possible, please explain it a bit more — DXB-DEV
– DXB-DEV, Commented Jun 20, 2024 at 11:42
maybe he meant like if you have the result (say something like const res = await db.findOne....) then const decimalValue = +res.orderAmount or if it returns multiple docs might have to .map through it and then convert — cmgchess
– cmgchess, Commented Jun 20, 2024 at 12:08

cmgchess · Accepted Answer · 2024-06-20 11:51:38Z

1

Here is a solution where the conversion is done on DB side using an aggregation instead of a find()

$toDouble

db.collection.aggregate([
  {
    $match: {
      // filter necessary like find()
    }
  },
  {
    $set: {   // or $addFields
      orderAmount: {
        $toDouble: "$orderAmount"
      }
    }
  }
])

playground

edited Jun 20, 2024 at 11:51

answered Jun 20, 2024 at 11:46

cmgchess

10.3k42 gold badges55 silver badges70 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

DXB-DEV Over a year ago

Thank you @cmgchess. Even if I had to modify my code to use aggregate() instead of find() , the issue is solved in the backend itself and the frontend is safe to use the API without any special handling for displaying the orderAmount field.

Collectives™ on Stack Overflow

How to convert Decimal128 value to Float value in Node.js / Mongoose?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related