Clash Royale CLAN TAG#URR8PPP

Is an ObjectId automatically generated for a nested object?

My schema is as follows:

const MessageType =
// ...
oAuth: provider: String, id: String ,
attachments: [ name: String, contentType: String ],
// ...

MessageSchema = new mongoose.Schema(MessageType, timestamps: true);
Messages = mongoose.model("Message", MessageSchema);


When I insert a new Message document using Messages.create, an ObjectId (_id) is also generated for attachments, in addition to my name and contentType fields, ie:

Messages.create

ObjectId

_id

attachments

name

contentType

[ name: "xxx", contentType: "yyy", _id: zzzzzz ]


Why is this happening, for attachments but not oAuth?

attachments

oAuth

2 Answers
2

You can define _id : false in attachments array.

_id : false

const MessageType =
// ...
attachments: [ name: String, contentType: String, _id: false ],
// ...



For avoiding that the _id was generated you must set the option _id: false, Also if you don't want to save the empty attachments object, you need to set default: undefined.

const MessageTypeSchema = new mongoose.Schema(
oAuth:
type: String
,
attachments:
type: [

type: String

],
_id: false,
default: undefined

);


Here the code that I used to test:

console.log('-------- Document with attachments --------');
new MessageTypeModel(
oAuth:'xxxxxxxxxxxxx',
attachments: ['teste.png','teste2.jpg']
).save().then(result =>
console.log(result);
);

console.log('-------- Document without attachments --------');
new MessageTypeModel(
oAuth:'xxxxxxxxxxxxx'
).save().then(result =>
console.log(result);
);


And here the result of execution:

_id

attachments

oAuth

_id

attachments

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