Linking Windchill information from EPM-tables and WTPart-tables

Hi Guys,

currently I´m trying to understand the database schema behind Windchill PDMLink.

My aim is to get all parts of an assembly, with all the attached information.

Now I have looked over some tables and foudn the links beetween them. But now I´m stuck!

How can I link the information from the EPMDocument (EPMDocumentMaster, ...)  with the WTPart (WTPartMaster, ...) tables?

WTPartMasterKey and EPMDocumentMasterKey both have the field WTKey, but the have different contents.

I´m using Windchill PDMLink 9.1.

Thanks in advance!

Ben