Hi,
Sometimes exposing data source as OData service fails due to a constraint imposed on EDM TSimpleIdentifier which has strict restrictions what is a valid column name. Here is an example:
http://accessindepth.blogspot.no/2011/03/sharepoint-2010-lists-odata-content.html
I had the same problem with my MongOData OData provider for MongoDB where I had to rename Mongo's "_id" property. But is still fails if it encounters what it believes "invalid" property name.
The blog post that I mentioned above says that "the pattern applied to the TSimpleIdentifier Entity Data Model data type that precludes leading underscores should be removed in a later EDM v4.1 CTP because the rule is arbitrary". It would be really nice if such wide protocol as OData wouldn't be controlled by very restrictive naming guidelines. So I wonder if there are any plans to list this restriction.
Best regards
Vagif Abilov