Decimal / Float in mongoose for node.js

Question

I start my first test app on node.js / mongoDB / mongoose, this is a very simple app that aims to crate record in DB and retrieve them.

I create a model like:

var Car = new Schema({
    brand : String,
    speed  : Number,
    date  :  { type: Date, default: Date.now }
});

This is working fine, except that I would like to be able to provide a float value for speed instead of the integer one. I gave a try to Decimal and Float but none of them are working. I did not find in the documentation either.

Any idea ?

var car = new Car({brand: "", speed: 0.5});

skeggse
– skeggse

2013-12-04 21:08:51 +00:00
Commented Dec 4, 2013 at 21:08 — skeggse
– skeggse, Commented Dec 4, 2013 at 21:08

Machavity · Accepted Answer · 2020-01-03 14:32:03Z

99

I've searched a bit and found this article stating that for storing float values you must use Number type. You can store any float value in speed field.

edited Jan 3, 2020 at 14:32

Machavity♦

31.8k27 gold badges97 silver badges108 bronze badges

answered Apr 9, 2011 at 20:32

Andrew Orsich

53.8k17 gold badges142 silver badges134 bronze badges

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

6 Comments

Luc Over a year ago

thanks a lot . But, in this article, it seems it's more the other way round, ie to force a float into an integer, right ? Sorry, I maybe misanderstood the thing.

Andrew Orsich Over a year ago

@Luc: Exactly, in article about forcing float into an integer. But it's mean that you can store float value in field with type Number. So Number type should be used for both types: integer and float.

Luc Over a year ago

@Bugain13, thanks a lot, you'r right. There is something strange I should have done because it was not working at first place. Thanks a lot for your help !!!!

Cloudscape Germany Over a year ago

You should be warned: When using number and aggregations like summations with Mongoose you will get Ulps problems. (insertion of a 1 after dozens of Zeros behind the point)

Ehsan Sarshar Over a year ago

it just convert float to int. and nothing else

|

Pranab Das · Accepted Answer · 2022-01-05 08:48:42Z

11

You can use the Decimal128 in Mongoose Schema as

speed:{
type:mongoose.Types.Decimal128
}

answered Jan 5, 2022 at 8:48

Pranab Das

1191 silver badge10 bronze badges

Comments

Machavity · Accepted Answer · 2020-01-03 14:37:57Z

10

Yes you can use the Decimal128 type.

https://mongoosejs.com/docs/api.html#mongoose_Mongoose-Decimal128

edited Jan 3, 2020 at 14:37

Machavity♦

31.8k27 gold badges97 silver badges108 bronze badges

answered Mar 28, 2019 at 11:20

Muzaffar Mahmood

1,9182 gold badges19 silver badges21 bronze badges

Comments

Ehsan Sarshar · Accepted Answer · 2020-06-21 07:36:19Z

2

you can create your custom one. like so

'use strict';

const mongoose = require('mongoose');

class DoubleType extends Number {
  constructor(v) {
    super(v);
    this.value = v;
    this._bsontype = 'Double';
  }

  toBSON() {
    return this;
  }
}

class Double extends mongoose.SchemaType {
  constructor(key, options) {
    super(key, options, 'Double');

    Object.assign(this.$conditionalHandlers, {
      '$lt': val => this.castForQuery(val),
      '$lte': val => this.castForQuery(val),
      '$gt': val => this.castForQuery(val),
      '$gte': val => this.castForQuery(val),
    });
  }

  cast(val) {
    if (val == null) {
      return val;
    }
    if (val._bsontype === 'Double') {
      return new DoubleType(val.value);
    }

    const _val = Number(val);
    if (isNaN(_val)) {
      throw new mongoose.SchemaType.CastError('Double',
        val + ' is not a valid double');
    }
    return new DoubleType(_val);
  }
}

mongoose.Schema.Types.Double = Double;
mongoose.Types.Double = DoubleType;

module.exports = Double;

source is copied from @mongoosejs/double

edited Jun 21, 2020 at 7:36

answered Jun 21, 2020 at 7:10

Ehsan Sarshar

3,2911 gold badge30 silver badges47 bronze badges

2 Comments

Ezequiel Tavares Over a year ago

Como faria o uso?

Ehsan Sarshar Over a year ago

@EzequielTavares waa

Community · Accepted Answer · 2024-03-07 11:08:57Z

-4

While the mongoDB fully supports float type, the mongoose supports only type of Number which is integer. If you try to save to mongoDB float number using mongooses type of Number it will be converted to string.

To sort this out, you will need to load some plugin for mongoose which will extend its value types. There are some plugins which work best with currencies or dates, but in your case I would use https://www.npmjs.com/package/mongoose-double.

Your model after changes would look something like this:

var mongoose = require('mongoose')
require('mongoose-double')(mongoose);

var SchemaTypes = mongoose.Schema.Types;
var Car = new Schema({
    brand: { 
        type: String 
    },
    speed: {
        type: SchemaTypes.Double
    },
    date: {
        type: Date, 
        default: Date.now 
    }
});

Hope it helps.

Edit: I have just found that in 2018, the mongoose added support for Decimal128 so you can simply just use mongoose.Types.Decimal128 for your schema

edited Mar 7, 2024 at 11:08

CommunityBot

11 silver badge

answered Feb 18, 2016 at 13:00

99problems

59413 silver badges28 bronze badges

1 Comment

JWindey Over a year ago

No it won't. You can store numbers like 25.50 as a number and it won't be stored as a string

Collectives™ on Stack Overflow

Decimal / Float in mongoose for node.js

5 Answers 5

6 Comments

Comments

Comments

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

6 Comments

Comments

Comments

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related