title: Counting occurrences of unique values in a column using sql
body: <p>Is there a simple way for counting occurrences of unique values in a column using sql.</p>
  
  <p>for e.g if my column is</p>
  
  <pre><code>a
  a
  b
  a
  b
  c
  d
  d
  a
  </code></pre>
  
  <p>Then the output should be</p>
  
  <p>a  4 <br />
  b  2 <br />
  c  1 <br />
  d  2 <br /></p>