Mongoose __v property - hide?

Question

Mongoose adds a '__v' property into Schema's for versioning - is it possible to disable this globally or globally hide it from all queries?

Possible duplicate of [What is the "\_\_v" field in Mongoose](https://stackoverflow.com/questions/12495891/what-is-the-v-field-in-mongoose) — KARTHIKEYAN.A, Oct 16 '19 at 07:46

score 119 · Accepted Answer · answered Dec 04 '12 at 20:28

119

You can disable the "__v" attribute in your Schema definitions by setting the versionKey option to false. For example:

var widgetSchema = new Schema({ ... attributes ... }, { versionKey: false });

I don't think you can globally disable them, but can only do it per Schema. You can read more about Schema's options here. You might also find the Schema set method helpful.

answered Dec 04 '12 at 20:28

theabraham

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is it safe to disable "__v" attribute? will it cause any future issue if I disable it? – Nam Nguyen Sep 10 '13 at 23:09
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Is there a way to hide it from the returned docs from queries? – Diosney Dec 14 '13 at 20:40
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Is it safe? You can read the details [here](http://aaronheckmann.tumblr.com/post/48943525537/mongoose-v3-part-1-versioning). TL:DR; Mongoose uses the version key to help avoid errors encountered by positional notation e.g. `$set: { 'comments.3.body': updatedText }`. If you read a document and use that update statement but someone modifies the `comments` array in the meantime you could update the wrong comment. With a version key you will get an exception in that case. – Pace Mar 27 '18 at 13:41

score 61 · Answer 2 · edited Mar 29 '20 at 18:03

61

To disable '__v' property, which is not recommended, use the versionKey schema option:

var Schema = new Schema({...}, { versionKey: false });

To hide it from all queries, which sometimes can be not what you want too, use the select schema type option:

var Schema = new Schema({ __v: { type: Number, select: false}})

edited Mar 29 '20 at 18:03

Mr. Alien

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answered Mar 16 '14 at 11:43

Alexander Gonchiy

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So how can I delete _id and __v before returning them to user? Is there any kind of mapping I can do? Mapping from schema to model would remove these two attributes and mapping from model to schema would let's say remove some fields user should not be able to edit but still see them. – Dread Boy Sep 23 '14 at 20:49

score 33 · Answer 3 · edited Mar 26 '15 at 03:22

33

Two ways:

{versionKey: false}
when you query, like model.findById(id).select('-__v')

'-' means exclude the field

edited Mar 26 '15 at 03:22

sqluser

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answered Mar 26 '15 at 02:35

EarthShaker

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score 24 · Answer 4 · answered Nov 22 '14 at 10:17

24

define a toObject.transform function, and make sure you always call toObject when getting documents from mongoose.

var SomeSchema = new Schema({
    <some schema spec>
  } , {
    toObject: {
      transform: function (doc, ret, game) {
        delete ret.__v;
      }
    }
});

answered Nov 22 '14 at 10:17

Amit Portnoy

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Alternatively you can call `user.toObject({ versionKey: false })`, which will hide `__v` version property. – FullStackForger Apr 10 '16 at 07:36
Do you also need `toJSON()`? – binki Jul 04 '17 at 17:19
@binki No, not needed – NIKHIL C M May 30 '20 at 09:23

score 8 · Answer 5 · answered Nov 25 '16 at 07:09

Try this it will remove _v from every query response.

// transform for sending as json
function omitPrivate(doc, obj) {
    delete obj.__v;
    return obj;
}

// schema options
var options = {
    toJSON: {
        transform: omitPrivate
    }
};
// schema
var Schema = new Schema({...}, options);

score 6 · Answer 6 · answered Jun 29 '16 at 06:14

6

You may not want to disable __v, other answers provide few links to answer why you shouldn't disable it.

I've used this library to hide the __v and _id

https://www.npmjs.com/package/mongoose-hidden

let mongooseHidden = require("mongoose-hidden")();

// This will add `id` in toJSON
yourSchema.set("toJSON", {
        virtuals: true,
    });

// This will remove `_id` and `__v` 
yourSchema.plugin(mongooseHidden);

Now __v will exist, but it won't be returned with doc.toJSON().

Hope it helps.

answered Jun 29 '16 at 06:14

Ashwani Agarwal

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Why use a library to do this silly simple transformation ? refer toJSON or toObject schema option instead. toObject() worked for me. – NIKHIL C M May 30 '20 at 09:24
You're right. Other answers have recommended the same thing. @NIKHILCM – Ashwani Agarwal Jun 01 '20 at 04:26

score 5 · Answer 7 · answered Sep 12 '20 at 15:30

You can use a Query Middleware to exclude any field from the output. In your case you can use this:

// '/^find/' is a regex that matches queries that start with find
// like find, findOne, findOneAndDelete, findOneAndRemove, findOneAndUpdate
schema.pre(/^find/, function(next) {
    // this keyword refers to the current query
    // select method excludes or includes fields using + and -
    this.select("-__v");
    next();
});

For more information in docs lookup: Middlewares select method

score -22 · Answer 8 · edited Sep 29 '17 at 19:04

-22

Yes, it is simple, just edit the "schema.js" file that is inside

"node_modules\mongoose\lib"

Search for "options = utils.options ({ ... versionKey: '__v'..." and change value "__v" to false.

This will change all post requests. (versionKey: '__v' => versionKey: false)

edited Sep 29 '17 at 19:04

Dmitry

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answered Sep 29 '17 at 17:57

Leandro Santana

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This is terrible advice. – arg20 Nov 29 '18 at 16:08
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You should not change code inside `node_modules`. The content of this folder changes often with npm install and it should be added to `.gitignore`. Whatever you write there will be lost. – Andréa Maugars Jan 21 '20 at 09:32

Mongoose __v property - hide?

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