Query to get workflow last comment in Ax 2012

I want to highlight Query to get workflow last comment in Ax 2012. You can use ,WorkflowTrackingTable,WorkflowTrackingStatusTable  and WorkflowTrackingCommentTable   to get Last comment entered by used on submitting or approving workflow for module

 WorkflowTrackingTable      workflowTrackingTable;  
   WorkflowTrackingStatusTable   workflowTrackingStatusTable;  
   WorkflowTrackingCommentTable  workflowTrackingCommentTable;  
 PurchTable PurchTable;  
 select PurchTable where PurchTable.PurchId ="PO13000003";  
   select ContextCompanyId, ContextTableId, ContextRecId from workflowTrackingStatusTable  
     where workflowTrackingStatusTable.ContextCompanyId  == curext()  
       && workflowTrackingStatusTable.ContextTableId   == PurchTable.TableId  
       && workflowTrackingStatusTable.ContextRecId    == PurchTable.RecId  
     join firstonly TrackingId, CreatedDateTime from workflowTrackingTable order by CreatedDateTime desc  
       where workflowTrackingTable.WorkflowTrackingStatusTable == workflowTrackingStatusTable.RecId  
     join Comment from workflowTrackingCommentTable  
       where workflowTrackingCommentTable.WorkflowTrackingTable == workflowTrackingTable.RecId;  
   info( workflowTrackingCommentTable.Comment);