New Discussion field in Team Member 8.4

How is the new discussion field in Team Member 8.4 tied to the "resourcehour" table in the database so that BI Reports can include the data associated with the timesheet hours on an activity with the comments in the discussion field?  Here are the two tables I would like to join for reporting discussions on a time sheet entry.

SELECT [pxrptuser].[ACTIVITYCOMMENT].[activityobjectid]

      ,[pxrptuser].[ACTIVITYCOMMENT].[commentid]

      ,[pxrptuser].[ACTIVITYCOMMENT].[userobjectid]

      ,[pxrptuser].[ACTIVITYCOMMENT].[commentdate]

      ,[pxrptuser].[ACTIVITYCOMMENT].[commenttext]

      ,[pxrptuser].[RESOURCEHOUR].[objectid]

      ,[pxrptuser].[RESOURCEHOUR].[resourceobjectid]

      ,[pxrptuser].[RESOURCEHOUR].[projectid]

      ,[pxrptuser].[RESOURCEHOUR].[projectname]

      ,[pxrptuser].[RESOURCEHOUR].[resourceid]

      ,[pxrptuser].[RESOURCEASSIGNMENT].[activityid]

  FROM [pxrptuser].[RESOURCEHOUR],[pxrptuser].[ACTIVITYCOMMENT]