title: Detect consecutive dates ranges using SQL
body: <p>I want to fill the calendar object which requires start and end date information. I have one column which contains a sequence of dates. Some of the dates are consecutive (have one day difference) and some are not.</p>
  
  <pre><code>InfoDate  
  
  2013-12-04  consecutive date [StartDate]
  2013-12-05  consecutive date
  2013-12-06  consecutive date [EndDate]
  
  2013-12-09                   [startDate]
  2013-12-10                   [EndDate]
  
  2014-01-01                   [startDate]
  2014-01-02 
  2014-01-03                   [EndDate]
  
  2014-01-06                   [startDate]
  2014-01-07                   [EndDate]
  
  2014-01-29                   [startDate]
  2014-01-30 
  2014-01-31                   [EndDate]
  
  2014-02-03                   [startDate]
  2014-02-04                   [EndDate]
  </code></pre>
  
  <p>I want to pick each consecutive dates range’s start and end date (the first one and the last one in the block).</p>
  
  <pre><code>StartDate     EndDate
  
  2013-12-04    2013-12-06
  2013-12-09    2013-12-10
  2014-01-01    2014-01-03
  2014-01-06    2014-01-07
  2014-01-29    2014-01-31
  2014-02-03    2014-02-04
  </code></pre>
  
  <p>I want to solve the problem using SQL only.</p>