title: Select difference of same value as of two dates from single table
body: <p>i have a select query selecting different columns and for one column i have to get a value from a table as of today and previous year end and should take the difference. Assume that this table stores values everyday suppose it to be X.</p>
  
  <pre><code>select a
         b
         c
         d
         e
  
  e= ( SELECT VALUE FROM X WHERE DATE='TODAY') MINUS ( SELECT VALUE FROM X WHERE DATE='PREVIOUS YEAR END') i.e 31-dec-2013
  </code></pre>
  
  <p>Can some one please tell me the logic how same value as of different dates can be selected in single select query</p>