title: Django Database List is empty even after publishing. DjangoGirls Tutorial
body: <p>I am working on <a href="http://tutorial.djangogirls.org/" rel="nofollow">DjangoGirls Tutorial</a> to create a blog. This is my first time with Django and more or less with Python too.</p>
  
  <p>Hi I ran into a problem. </p>
  
  <p>Whatever I do, my <code>Post.objects.filter(published_date__isnull=False)</code> command still shows an empty list. Below is the commands and outputs:</p>
  
  <pre><code>&gt;&gt;&gt; post = Post.objects.get(id=1)
  &gt;&gt;&gt; post.publish()
  &gt;&gt;&gt; Post.objects.filter(published_date__isnull=False)
  []
  &gt;&gt;&gt; post = Post.objects.get(id=2)
  &gt;&gt;&gt; post.publish()
  &gt;&gt;&gt; Post.objects.filter(published_date__isnull=False)
  []
  &gt;&gt;&gt; first = Post.objects.get(id=1)
  &gt;&gt;&gt; first.publish()
  &gt;&gt;&gt; Post.objects.filter(published_date__isnull=False)
  []
  </code></pre>
  
  <p>Can someone help me understand what I am doing wrong?
  I have these many posts in my database:</p>
  
  <pre><code>&gt;&gt;&gt; Post.objects.all()
  [&lt;Post: Sample Title&gt;, &lt;Post: Sample-1 Title&gt;, &lt;Post: Sample-2 Title&gt;, &lt;Post: Sample-3 Title&gt;, &lt;Post: Sample-4 Title&gt;, &lt;Post: Sample-5 Title&gt;, &lt;Post: Sample-6 Title&gt;]
  </code></pre>
  
  <p>And I have these many authors in the database:</p>
  
  <pre><code>&gt;&gt;&gt; User.objects.all()
  [&lt;User: ola&gt;, &lt;User: dola&gt;, &lt;User: bula&gt;, &lt;User: kela&gt;, &lt;User: lala&gt;]
  </code></pre>
  
  <p>I can't understand what's wrong then. Of course, this problem did not affect the project. I am continuing with the rest of the tutorial and it's going fine. Thanks.</p>