Hello there!

i have to connect a 3rd party db-system (Microsoft Navision) for read-only.
There are several different object (table)-versions, so i need to handle different versions of the tables.

i thougth about some solutions, here is what i got:

1: No entities, just business-Objects and a version-depending Facade to execute native SQL.
pro: most compatible
contra: own mapping -> huge effort

2: business- & entity-pack for each version (also different persistence units)
pro: reliable business-logics
contra: do all x times seperately (business & enitities for each version), interfaces for all beans

3: unified version of entities with all non-common attributes as "transient", reload these attributes according to table-version afterwards (native SQL)
pro: compatible entity with all db-versions
contra: hibernate cannot search with transient attributes, performance-issue on collections

you have any suggestions how to realize a versioning to support different 3rd-party db-versions (or better table-versions)?