Cascading save not working

[khushroo-mistry]

Hi there,

I am trying to perform a cascading save but not found any success yet:
In summary all I want to do it update the parent model and the child collection (add the new one remove the old not required ones and update what is updated). Excuse my code its just POC. Please help answer my query.

DB Config file

'use strict';

var knex = require('knex')({
    client: 'mysql',
    connection: {
        host     : 'localhost',
        user     : 'root',
        password : 'root',
        database : 'rocket-poc',
        charset  : 'utf8'
    }
});

module.exports = require('bookshelf')(knex);

Model Declarations

'use strict';

var bookshelf = require('./db-config');

bookshelf.plugin('bookshelf-manager');

exports.getOpportunityModel = function(){

    var Opportunity = bookshelf.Model.extend({
        tableName: 'opportunity',
        livingExpenses: function() {
            return this.hasMany(LivingExpenses);
        }
    });

    var LivingExpenses = bookshelf.Model.extend({
        tableName: 'living_expenses'
    });

    return {
        Opportunity:Opportunity,
        LivingExpenses:LivingExpenses

    };

};

The Consumer

'use strict';

var opty = require('./opportunityModel');

var bookshelf = require('./db-config');

bookshelf.plugin('bookshelf-manager');

exports.operations = function(){

    return new opty.getOpportunityModel().Opportunity.where('id', 1).fetch({withRelated: ['livingExpenses']})
        .then(function(opportunity){
            //console.log(opportunity.toJSON());
            var livingExp1 = {description: "some this", value: 900};
            var livingExp2 = {description: "some this", value: 1900};

            //var le = new opty.getOpportunityModel().LivingExpenses();

            //console.log(le);

            return opportunity;

        })
        .then(function(opportunity){
            //console.log(opportunity);

            var optyOriginal  = opportunity;

            //opportunity.livingExpenses().a;
            var livingExp1 = {description: "some this", value: 1900, opportunity_id: 1};
            var livingExp2 = {description: "some this", value: 2300, opportunity_id: 1};

            var optyEx = opportunity.related('livingExpenses').set([livingExp1, livingExp2]);

            console.log(opportunity.toJSON());

            //return opportunity.save(null, {withRelated: ['livingExpenses']});

            return bookshelf.manager.save(optyOriginal, optyEx.toJSON());





        }).then(function(model){

            console.log(JSON.stringify(model));

            return Promise.resolve("done");
        })
        .catch(function(err){
            console.error(err);
            return Promise.reject(err);
        });


};