Meteor change database at run time Ask Question

I have three database i.e, main_db it is default load database. I want load database after login.
Database are:-

main_db

->user_collection

psm_2017_db

->abc_collection

->xyz_collection

psm_2018_db

->abc_collection

->xyz_collection

Here is my project structure

[![enter image description here][1]][1]

here is my login script.

client
 |->login
  |->login.js
  
            Template.login.rendered = function(){
            SessionStore.set("login_user",false);
            };
            Template.login.events({
                'submit #formLogin': function (event, target){
                    event.preventDefault();
                    var email = target.find('#loginEmail').value;
                    var password = target.find('#loginPassword').value;
                    // console.log(email +" "+password);
                    Meteor.loginWithPassword(email, password, function(err){

                        if(err){
                        console.log(err);
                            alert("Invalid Login!");
                        }
                        else {
                        SessionStore.set("login_user",true);
                            console.log('successfully')
                            Router.go("/dashboard")
                        }
                    });
                }
            });

            Template.layout.helpers({
            "isLoggedin": function () {
                return SessionStore.get("login_user");
            }
            });

here is my load collection file

lib
 |->collection.js

     abcCollection=new Mongo.Collection("abc_collection");         
     xyzCollection=new Mongo.Collection("xyz_collection");

28 AM