title: Group By a nullable column
body: <p>As you know Oracle treats NULLs as one "value" in GROUP BY queries. Is there a workaround solution to group data treating NULLs as different values each. For example:</p>
  
  <p>table t:</p>
  
  <pre><code>colA     colB
   A         1 
   A         5 
  &lt;null&gt;     3 
  &lt;null&gt;     2
  </code></pre>
  
  <p><code>select colA, min(colB) from t group by colA</code> returns:</p>
  
  <pre><code>colA     colB
   A         1 
  &lt;null&gt;     2
  </code></pre>
  
  <p>but i want a query to return:</p>
  
  <pre><code>colA     colB
   A         1 
  &lt;null&gt;     3 
  &lt;null&gt;     2
  </code></pre>
  
  <p>Thanks in advance</p>