I need to understand the connection between wtpart and epmdocument. Somehow windchill has to know how the two "things" belong together. To undestand this I went deep and used some sql selects. Until now I thought, that a wtpart and a epmdcoument are connected by epmdescribelink, but now I have two "things" which are connected (windchill shows me that) but there is no link in epmdescribelink.
Why do I have to know? Over the years our datas has been maintained by different people with different approaches. So we have now a "mixed salad" of data. I want to clean this mess up and for that I need to analyse the different situations. So understanding the windchill data model is base to this task. So how could I gain this precious knowledge?
It's actually much more complex:
- Different WTPart Views (Design, Manufacturing for example)
- Build status can be pending, complete
- Alternates and Substitutes can be applied
- CAD can be related thru various link types: Owner, Image, Contributing Image, etc.
- When using multiple CAD systems (both MCAD and ECAD) there can be multiple CAD Docs for a single WTPart
- Various "Config Specs" can be applied (Promotion, Baseline, Latest, Latest Released) to determine which versions of CAD Docs are selected for a given WTPart
Play with all this on a rehosted test system.
Mike is correct... but more narrowly, EPMDescribeLink covers "Content" links between WTPart and EPMDocument; for other links, also check out EPMBuildRule:
select buildtype, documentnumber, epmdocument.versionida2versioninfo, epmdocument.iterationida2iterationinfo , wtpartnumber, wtpart.versionida2versioninfo, wtpart.iterationida2iterationinfo
inner join epmdocument on epmdocument.branchiditerationinfo = epmbuildrule.branchida3a5 and
epmdocument.latestiterationinfo = 1
inner join epmdocumentmaster on epmdocumentmaster.ida2a2 = epmdocument.ida3masterreference
inner join wtpart on wtpart.branchiditerationinfo = epmbuildrule.branchida3b5 and wtpart.latestiterationinfo = 1
inner join wtpartmaster on wtpartmaster.ida2a2 = wtpart.ida3masterreference
EPMBuildHistory is interesting too...
If you see a "Calculated Link" in the UI, that isn't actually a link - it's "calculated" when you view the screen.
I don´t know all the details but all the points Mike exposed are correct, it is possible that for each case the data model behaves differently.
So far, I know this at database level: