[OLINGO-42] jpa processor requires a redundant field for many-to-one relationships

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: V2 1.0.0
• Fix Version/s: V2 1.1.0
• Component/s: odata2-jpa
• Environment: windows7, tomcat 7.0.42, hsql, eclipse link 2.5.0
• Assignee: Chandan V.A
• Reporter: Georgi
• Created: 25/Oct/13 09:00
• Updated: 10/Feb/14 15:15
• Resolved: 17/Jan/14 18:49

Description

It looks like that the only way to get a consistent EDM associations model and the corresponding navigation properties, when there are many-to-one (bi-directional) managed relationships, is to add an additional and redundant property, annotated with @Column to the owning class. Same as in your reference jpa model.
However, it's highly unlikely that one models a JPA model like this in reality and quite an impairment particularly for existing models.
I'm not sure why is that needed, because the information encoded in the required field @Column annotation is redundant with the one @JoinColumn annotation and you already parse the JoinColumn anyways.
So probably that's a low hanging fruit?

I also realized that specifying the optional in the JPA @JoinColumn annotaiton property referencedColumnName is yet another mandatory requirement for the JPA edm producer to create a valid navigation properties set.