title: Converting Oracle date arithmetic to work in HSQLDB
body: <p>I'm trying to spot-test an Oracle backed database with hsqldb and dbunit, but I've run into a snag.</p>
  
  <p>The problem is with the following EJB-QL (simplified a bit):</p>
  
  <pre><code>SELECT o 
  FROM Offer o 
  WHERE :nowTime 
    BETWEEN o.startDate AND o.startDate + 7
  </code></pre>
  
  <p>This seems to only work in Oracle's version of SQL.</p>
  
  <p>What's the easiest way for me to convert this to work in both hsqldb and oracle?  Assume that changing the two between arguments to named parameters is a very difficult refactor, so I'm going to favor answers that provides a more standardized analog to <pre>o.startdate + 7</pre></p>
  
  <hr>
  
  <p>EDIT:
  After doing some more research, it looks like Oracle converts the above snippet to <pre>o.startdate + INTERVAL '7' DAY</pre> which is apparently more standard, but doesn't work in HSQLDB. </p>