Below is the SQL which I use for change objects, might need a bit of tuning as per your requirement. You can get more details about the workflow data model from the PTC CS https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS153902 and I find it really useful
SELECT A2.classnameA2A2,A2.idA2A2,A2.role C1C1,A2.eventList C1C2,TO_CHAR(A3.deadline,'dd mm yyyy hh24:mi:ss') C1C3,TO_CHAR(A2.modifyStampA2,
'dd mm yyyy hh24:mi:ss') C1C4,TO_CHAR(A7.modifyStampA2,'dd mm yyyy hh24:mi:ss') C1C5 FROM WfProcess A0,ControlBranch A1,WfVotingEventAudit A2,WfAssignedActivity A3,
WTChangeActivity2 A4,WTChangeActivity2Master A5,WTChangeOrder2 A6,WorkItem A7,WfAssignment A8,IncludedIn2 A9,ActivityAssignmentLink A10,WorkItemLink A11 WHERE (((A0.wtkey = A2.processKey)
AND (A3.wtkey = A2.activityKey) AND (A0.businessObjReference = ('VR:wt.change2.WTChangeActivity2')||(A1.idA2A2)))) AND (((A9.branchIdA3A5 = A6.branchIditerationInfo) AND (A6.latestiterationInfo = 1))
AND ((A9.branchIdA3B5 = A4.branchIditerationInfo) AND (A4.latestiterationInfo = 1))
AND (A10.idA3A5 = A3.idA2A2) AND (A10.idA3B5 = A8.idA2A2) AND (A11.idA3A5 = A8.idA2A2) AND (A11.idA3B5 = A7.idA2A2) AND (A4.idA3masterReference = A5.idA2A2) AND (A1.idA3B5 = A5.idA2A2))
Thank you,
Binesh Kumar