title: SQL select query for Days count from Registration Date
body: <p>SQL select query for days count from registration date. I have a column RegistrationDate in my <code>Registration</code> table in my SQL Server 2008 database.</p>
  
  <p>Suppose I have a <code>registrationDate</code> like this:</p>
  
  <pre><code>2016-12-10
  </code></pre>
  
  <p>and suppose today is <code>2016-12-20</code>, then the output should be like:</p>
  
  <pre><code>registrationDate     registrationAge     
    2016-12-10             10 days
  </code></pre>