I have at first sight a simple issue but can't wrap my head around on how to solve. I have an abstract class Compound. A Compound is made up of Structures. Then there is also a Container which holds 1 Compound.A special implementation of Compound has Versions. For that type of Compound I want the Container to hold the Versionof the Compound and not the Compound itself.You could say just create an interface Containable and a Container holds 1 Containable. However that won't work. The reason is I'm creating a framework and the main part of that framework is to simplify storing and especially searching for special data type held by Structure objects. Hence to search for Containers which contain a Compound made up of a specific Structure requires that the Path from Containerto Structure is well defined (Number of relationships or joins). I hope this was understandable. My question is how to design the classes and relationships to be able to do what I outlined.EDIT:Kind of translation issue. with version i did not mean in terms of versioning but more in terms of different variety but fundamentally the same. There is no active / inactive. All are active.EDIT 2:Also note that these classes are entity classes and hence complex inheritance and hierarchies can be problematic.EDIT 3:Just don't see how either pattern (Composite, decorator) can work. I tried but the problem is the path traversal, eg. implementing it in the context of Spring-data and QueryDSL.I've created Class diagramm with comments that might help to understand the issue. Batch = Version.
OOP Design: relationship between entity classes
design;object oriented;orm;frameworks
The solution I used is this:And to reference the image in the question, a Batch extends Containable.