title: WSO2 DSS not working properly while i am sending this query in to postgres database its showing errors
body: <p>it is bug of WSO2DSS or its doesn't has future of it 
  i am sending epoch value from WSO2 ESB to WSO2 DSS and firing this customized query</p>
  
  <pre><code>INSERT INTO public.emp2(e_device,e_amount,e_no,jointime) VALUES(?,?,?,(SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 15555565225/1000 * INTERVAL '1 second'))
  </code></pre>
  
  <p>but its showing error My DSS config is like this</p>
  
  <pre><code>&lt;query id="insert_emp2_query" useConfig="default"&gt;
        &lt;sql&gt;INSERT INTO public.emp2(e_device,e_amount,e_no,jointime) VALUES(?,?,?,(SELECT TIMESTAMP  'epoch' + ?/1000 * INTERVAL '1 second'))&lt;/sql&gt;
        &lt;param name="e_device" ordinal="1" sqlType="STRING"/&gt;
        &lt;param name="e_amount" ordinal="2" sqlType="STRING"/&gt;
        &lt;param name="e_no" ordinal="3" sqlType="INTEGER"/&gt;
        &lt;param name="jointime" ordinal="4" sqlType="TIMESTAMP"/&gt;
     &lt;/query
  </code></pre>
  
  <p>the error of WSO2 DSS side is this</p>
  
  <pre><code>Nested Exception:-
  java.lang.NumberFormatException: date string can not be less than 19 characters
  
  &lt;soapenv:Reason&gt;
        &lt;soapenv:Text xml:lang="en-US" xmlns:xml="http://www.w3.org/XML/1998/namespace"&gt;DS Fault Message: Error in DS non result invoke.
  DS Code: DATABASE_ERROR
  Nested Exception:-
  javax.xml.stream.XMLStreamException: DS Fault Message: Error in 'SQLQuery.processNormalQuery'
  DS Code: DATABASE_ERROR
  Source Data Service:-
  Name: emp2_DataService
  Location: /emp2_DataService.dbs
  Description: N/A
  Default Namespace: http://ws.wso2.org/dataservice
  Current Request Name: insert_emp2_operation
  Current Params: {jointime=1361855692325, e_amount=5, e_no=5, e_device=5}
  Nested Exception:-
  java.lang.NumberFormatException: date string can not be less than 19 characters
  
  &lt;/soapenv:Text&gt;
     &lt;/soapenv:Reaso
  </code></pre>