Symfony2访问存储库查询结果的外键在php

使用find all repository方法时如何访问查询结果中的外键。特别是Jobs_id外键，它被提取到jobs对象中。

$entities = $em->getRepository('btBundle:workHours')->findAll();
    $em = $this->getDoctrine()->getManager();
using  foreach ($entities as $test) {
        $Id=$test->getId();  //Works fine
        $jobs=$test-getJobs(); // retrieves Jobs object.
        $jobs->getId(); // Error: Call to a member function getid() on a non-object   
}

就像它说的，它不是一个对象，我试着把它当作一个数组，比如

$jobs[0];
$jobs['id'];

给出错误error: Cannot use object of type代理…'Entity'Jobs as array

Jobs {#709 ▼
  #clients: Clients {#710 ▶}
  #company: Company {#638 ▶}
  #scopes: PersistentCollection {#711 ▶}
  #workHours: PersistentCollection {#713 ▶}
  #userDetails: PersistentCollection {#715 ▶}
  -id: 101
  -description: "Test Job"
  -jobNumber: "7844.00"
  -task: null
  -currencies: "USD"
  -active: 1
}