Mongoose schema

Question

I have these mongoose schemas:

var ItemSchema = new Schema({
    "pieces": Number, 
    "item": { type: Schema.Types.ObjectId, ref: 'Items' }
});

var cartSchema= new Schema({
    "items": [ItemSchema]
});

but when I want to push a new item in items, mongoose add an _id field(on the new item) but I don't understand why.

Related http://stackoverflow.com/questions/16881832/ – chridam Apr 13 '16 at 19:24 — chridam, Apr 13 '16 at 19:24

Abhyudit Jain · Answer 1 · 2016-04-13T19:40:40.973

1

Mongoose assigns each of your schemas an _id field by default if one is not passed into the Schema constructor. The type assigned is an ObjectId to coincide with MongoDB's default behavior. If you don't want an _id added to your schema at all, you may disable it using this option.

You can only use this option on sub-documents. Mongoose can't save a document without knowing its id, so you will get an error if you try to save a document without an _id.

Link: http://mongoosejs.com/docs/guide.html#_id

edited Apr 13 '16 at 19:40

answered Apr 13 '16 at 19:23

Abhyudit Jain

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No. I found that I can remove the _id field with `{ _id: false }` – Lorenzo Apr 13 '16 at 19:26
You can only use this option on sub-documents. Mongoose can't save a document without knowing its id, so you will get an error if you try to save a document without an _id. – Abhyudit Jain Apr 13 '16 at 19:39
Infact I wanted to delete _id field on sub-document – Lorenzo Apr 13 '16 at 19:45
you should've been more clear in the question. No worries... Can you accept this answer? – Abhyudit Jain Apr 13 '16 at 19:46

score 1 · Accepted Answer · answered Apr 14 '16 at 07:01

1

if you want to add item without _id field then you should add { _id: false } in ItemSchema.

var ItemSchema = new Schema({
    "pieces": Number, 
    "item": { type: Schema.Types.ObjectId, ref: 'Items' }
}, { _id: false });

answered Apr 14 '16 at 07:01

Shaishab Roy

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Mongoose schema

2 Answers2