title: limit the number of objects returned in a has_many
body: <p>How can I limit the number of rows returned in a has many relationship? For example:</p>
  
  <pre><code>class User &lt; ActiveRecord::Base
    has_many :photos
  end
  </code></pre>
  
  <p>I want to be able to do:</p>
  
  <pre><code>User.includes(:photos =&gt; {:limit =&gt; 8}).all
  </code></pre>
  
  <p>This obviously doesnt work, but something with this functionality. Do I need to write out the SQL myself?</p>
  
  <p>Thanks in advance!</p>
  
  <p>EDIT:
  I dont want to limit the association, just the query results. So a User might have a thousand photos, I only want the top 3 returned.</p>