Mongoose.populate() not showing any change in DB - node.js

Question

I have been trying to populate from a user table and have been unsuccessful. Any help would be appreciated.
I am checking a variable isProvider
if(true)
then the data is saved in a provider table
else
in a customer table.
I want the user table to be an Auth table, so I want to populate a field called "userId" in these models. The id is being saved. When i print the results of populate, It shows a populated json but when i see it in the database it shows only the Id. I want to access the details of user table through the photographer table. How do i achieve this ?
User model
/*
* Title: User model
*/
var mongoose = require('mongoose'),
Schema = mongoose.Schema,
passportLocalMongoose = require('passport-local-mongoose');
var bcrypt = require('bcrypt-nodejs');
//Data model
var UserSchema = new Schema({
email: {
type: String,
unique: true,
required: true
},
password: {
type: String,
required: true
},
token: String,
mobile: String,
type: String,
createdOn: {type: Date, default: Date.now},
lastModifiedOn: {type: Date},
deleted: {type: Number, default: 0},
isPhotographer: {type: Boolean, default: false},
verified: {type: Boolean, default: false}
});
UserSchema.pre('save', function(next) {
var user = this;
if(this.isModified('password') || this.isNew) {
bcrypt.genSalt(10, function (err, salt) {
if(err) {
return next(err);
}
bcrypt.hash(user.password, salt, null, function (err, hash) {
if ( err) {
return next(err);
}
user.password = hash;
next();
});
});
} else {
return next();
}
});
UserSchema.methods.comparePassword = function (passw, cb) {
bcrypt.compare(passw, this.password, function( err, isMatch) {
if(err) {
return cb(err);
}
cb(null, isMatch);
});
};
UserSchema.plugin(passportLocalMongoose);
user = mongoose.model('User', UserSchema);
module.exports = user;
Provider model
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
var User = require('./User');
//Data model
var providerSchema = new Schema({
userId: {
type: Schema.Types.ObjectId,
ref: 'User'
},
firstName: String,
lastName: String,
profilePicture: {
type: mongoose.Schema.Types.ObjectId,
ref: 'GFS'
},
email: String,
phone: Number,
address: String,
dob: Date,
createdOn: {type: Date, default: Date.now},
lastModifiedOn: {type: Date},
deleted: {type: Number, default: 0},
});
providerSchema.pre('save', function(next) {
this.lastModifiedOn = new Date;
next();
});
provider= mongoose.model('provider', providerSchema);
module.exports = provider;
Customer model
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
var User = require('./User');
//Data model
var customerSchema = new Schema({
userId: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User',
},
firstName: String,
lastName: String,
createdOn: {type: Date, default: Date.now},
lastModifiedOn: {type: Date},
deleted: {type: Number, default: 0},
});
customerSchema.pre('save', function(next) {
this.lastModifiedOn = new Date;
next();
});
customer = mongoose.model('Customer', customerSchema);
module.exports = customer;
Controller
if(user.isProvider) {
var provider= new providermodel({
userId: user._id,
firstName: req.body.firstName,
lastName: req.body.lastName
});
provider.save(function(err, docs) {
if(!err) {
pprovidermodel.findOne({_id: provider._id}).populate('userId').exec(function(err, docs) {
if(err) {
console.log(err);
}
else {
console.log(docs); ----> **Here populate works, but no changes in the database**
console.log("SO " + docs.userId.email);
}
})
}
})
}else {
var customer = new customermodel({
userId: user.id,
firstName: req.body.firstName,
lastName: req.body.lastName
});
customer.save(function(err) {
if(!err) {
customermodel.findOne({}).populate('userId').exec(function(err, docs)
{
console.log(err);
console.log(docs);
})
}
})
}

Answer 1

I think it's right. Populate don't change values in database only retrieve values when code is running.