title: RoR legacy database - associations crash system down
body: <p>I'm struggling with my Ruby on Rails App that has a legacy database. 
  It works in general but now I'm trying to show the associations created in the database. </p>
  
  <p>The two relevant scaffolds are called <code>repo</code> and <code>build</code>.</p>
  
  <p>One <code>repo has many builds</code> - so I have a foreign key <code>repo_id</code> in my builds table.</p>
  
  <p>The problem is the following:</p>
  
  <ul>
  <li>calling <code>repo/7</code> in browser is working</li>
  <li>calling <code>repo/7/builds/8</code> is also working</li>
  <li>but if I call <code>repo/7/builds</code> my system is crashing down ;)</li>
  </ul>
  
  <p>Furthermore I can do that in the rails console without any problems, like that:</p>
  
  <pre><code>r = Repo.find(7)
  r.builds 
  </code></pre>
  
  <p>--> returns all builds belonging to repo with id 7</p>
  
  <p>Does anyone know what's going wrong here?
  Thanks in advance!</p>