: EJB 3, JPA (EcipseLink) and Oracle Database
An application has two entities: Group and Person. There is a one-to-many relationship.
The requirement is, that every changes of Group and Person must be saved for later to roll or show.
The 1st idea:
make the id and timestamp of the change/create as a composite primary key for Group and Person. Every change will create a new object with the same id and new timestamp. For Example, a Group hat been changed, then create a new Group. but the relationship between Group and Person unchange. Here hat a problem: the constrait "one-to-many" will breaked!. Now one person hat the relation to two groups with the same id.
The 2nd idea:
for Group and Person create two another Entities GroupArchive and PersonArchive. In Group and Person only the lastest Infomation. Any changes will be copied and saved to Archive Entities. Between Group and GroupArchive hat a one-to-many relationship. And same for Person and PersonArchive.
Are my ideas realizable? Has anybody a better idea?
