title: SQL query to add column datediff calculated in months
body: <p>in the ms access database </p>
  
  <p>columnA has date entries</p>
  
  <pre><code>collumnA
  01/15/08
  02/11/08
  12/23/08
  </code></pre>
  
  <p>how do i write a query to add new column called months. </p>
  
  <p>where months are calculated as</p>
  
  <p>months = no. of months between  original date to 01 dec 2009</p>