The object oriented database, db4o, includes different queries types like native queries which are type safe. Another query is called Simple Object Database Access (SODA) query which internally uses object trees and string constraint representations. JDOQL is an object-oriented query language defined in the industry standard JDO. Now, JDOQL could be mapped directly to db4o's queries. More specific, JDOQL could be translated into SODA Query.
We apply a pragmatic software engineering approach (c.f. HinweiseAnStudienarbeiter). Its important to deliver a functioning library with mentioned demonstration cases.