title: SQL how to make one query out of multiple ones
body: <p>I have a table that holds monthly data of billing records. so say <code>Customer 1234</code> was billed in Jan/Feb and <code>Customer 2345</code> was billing Jan/Feb/Mar. How can I group these to show me a concurrent monthly billing cycle. But also need to have non-concurrent billed months, so <code>Customer 3456</code> was billed Feb/Apl/Jun/Aug</p>
  
  <pre><code>SELECT custName, month, billed, count(*) as Tally
  FROM db_name
  WHERE
  GROUP BY
  </code></pre>
  
  <p>Results needed:</p>
  
  <pre><code>Customer 1234 was billed for 2 months Concurrent
  Customer 2345 was billed for 3 months Concurrent
  Customer 3456 was billed for 4 months Non-Concurrent
  </code></pre>
  
  <p>Any suggestions?</p>