title: Why sqlite return null for count(*) with group by query?
body: <p>If I do simple query, for:</p>
  
  <pre class="lang-sql prettyprint-override"><code>select count(*) from emails
  where id &lt;= 0
  </code></pre>
  
  <p>It returns one row of zeros.</p>
  
  <p>However, if I group by the query, for:</p>
  
  <pre><code>select count(*) from emails
  where id &lt;= 0
  group by emails.id
  </code></pre>
  
  <p>It returns no rows.</p>
  
  <p>Why then behave differently and how to modify the second query to achieve the same behavior of the first one?</p>
  
  <p>The command line ouputs:</p>
  
  <pre><code>sqlite&gt; select count(*) from emails where id &lt;= 0;
  0
  sqlite&gt; select count(*) from emails where id &lt;= 0 group by emails.id;
  sqlite&gt; 
  </code></pre>