title: Django: getting FIRST item that belongs to a model object in a ManyToManyField
body: <p>Having a model <code>po</code> with a <code>ManyToManyField</code> called <code>Order</code>. </p>
  
  <p>I am considering some options including the following solutions:</p>
  
  <pre><code>po.Orders.all()[0].itemname
  </code></pre>
  
  <p>but I am not sure if this solution will be expensive (or not?) basically its querying for the whole table then filter out the first item.</p>
  
  <p>Second solution</p>
  
  <pre><code>po.Orders.get(pk=1).itemname
  </code></pre>
  
  <p>This one seem less expensive but doesn't work because its not possible to know the <code>pk</code> before hand.</p>
  
  <p>I'm wondering if there are other solutions that will obtain ANY item having the ManyToMany relationship with the <code>po</code> object?</p>