如何在php中使用多个实体管理器和连接

I am using Codeigniter 3 for my application and I created two database connections i.e Company and History. Now I want to make 2 queries where query 1 call company entity manager and second query call History Entity manager. These query should be called in one function where i get stuck

here is my code

$companies=$this->em->getRepository('comEntities\Company')->findAll();

$histories=$this->em->getRepository('HistoryEntities\History')->findAll();

This is the error which I get

Message: require(C:\xampp\htdocs\myApp\application\models/companies\comEntities\Company.php): failed to open stream: No such file or directory

Filename: third_party/ClassLoader.php

Line Number: 181