What is difference type of nested document in mogoose?

Question

During investigating mongoose nested document, i found that it has number of ways.

/*
Collection : profiles

{
    "name":"terry",
    "address":{
                "zipcode":135090,
                "city":"seoul",
                "state":"kyungki"
    },
    "birthday":"1975-03-03",
    "meta":{
            "company":"cloud consulting",
            "book":"architecture design"
            },
    "image":{
            "data":"xxxxxxx",
            "contentType":"image/png"
            }
}
*/

var mongoose = require('mongoose');
var fs = require('fs');
mongoose.connect('mongodb://localhost:27017/mydb');

var addressSchema = new mongoose.Schema({
    zipcode : Number,
    city : String,
    state : String
});


var profileSchema = new mongoose.Schema({
    name : String,
    address : addressSchema,
    birthday : Date,
    meta : mongoose.Schema.Types.Mixed,
    image : {
        data : Buffer,
        contentsType : String
    }
});

var Profile = mongoose.model('profiles',profileSchema);
var Address = mongoose.model('address',addressSchema);
var p = new Profile();

p.name = "terry";

// address
var a = new Address();
a.zipcode = 135090;
a.city = "youngin";
a.state = "Kyungki";
p.address = a;

// birthday
p.birthday = new Date(1970,05,10);

// meta
p.meta = { company : 'cloud consulting', book : 'architecture design'};

// image
p.image.contentsType='image/png';
var buffer = fs.readFileSync('/Users/terry/nick.jpeg');
p.image.data = buffer;

p.save(function(err,silece){
    if(err){
        cosole.log(err);
        return;
    }
    console.log(p);
});

as you can see, address, meta and image fields are nested document. For address field i created addressSchema field and meta field i used Mixed type in mongoose. and for the image field i just defined the nested document in the ProfileSchema.

I used 3 different ways, but i dont know what is difference between them.

Could u plz kindly give me a hint for this? Thanx in advance.

Possible duplicate of [Mongoose subdocuments vs nested schema](http://stackoverflow.com/questions/15208711/mongoose-subdocuments-vs-nested-schema) — Zeeshan Hassan Memon, Mar 28 '16 at 07:40

score 1 · Accepted Answer · answered Mar 28 '16 at 07:37

According the document saved in the db

{ "_id" : ObjectId("56f8dc3de430d672036bf325"), "meta" : { "book" : "architecture design", "company" : "cloud consulting" }, "birthday" : ISODate("1970-06-09T16:00:00Z"), "address" : { "_id" : ObjectId("56f8dc3de430d672036bf326"), "zipcode" : 135090, "city" : "youngin", "state" : "Kyungki" }, "name" : "terry", "image" : { "data" : "test is here...", "contentsType" : "image/png" }, "__v" : 0 }

We can get the difference among them,

address : addressSchema, which is sort of sub-doc, one additional _id could be found in address field, "address" : { "_id" : ObjectId("56f8dc3de430d672036bf326"), "zipcode" : 135090, "city" : "youngin", "state" : "Kyungki" }
image : {data : Buffer, contentsType : String} is pure nested document, there are only defined fields in image.
meta : mongoose.Schema.Types.Mixed, you can define an "anything goes" SchemaType, its flexibility comes at a trade-off of it being harder to maintain. refer to doc.

What is difference type of nested document in mogoose?

1 Answers1