title: BigQuery SQL same column multiple expressions
body: <p>I'm using Google's Big Query service to do some data processing...my database looks like:</p>
  
  <pre><code>value
  -----
  
  'a'
  'b'
  'a'
  'a'
  'a'
  'b'
  </code></pre>
  
  <p>I want to write a query to count the occurrences of the various values.</p>
  
  <p>Example:</p>
  
  <pre><code>Count('a')   Count('b')
  ----------   ----------
  4             3
  </code></pre>
  
  <p>I'd normally use Case to solve this; but BQ doesn't support Case.</p>
  
  <p>Anyone have any ideas?</p>
  
  <p>Thanks!</p>