Support relationships between views

[spassignat]

Hello,
If we have a model like User -->* Role mapped on views RoleView, UserView, read operation works very well, but schemaTool (or auto-create) does not know how to deal with that situation.

I tested it on version 5.2 and the latest 6.0 available and didn't find in groups.io information. Please find the attached testcase.

Here is the Exception:
java.lang.ClassCastException: class org.datanucleus.store.rdbms.mapping.java.BigIntegerMapping cannot be cast to class org.datanucleus.store.rdbms.mapping.java.MultiMapping (org.datanucleus.store.rdbms.mapping.java.BigIntegerMapping and org.datanucleus.store.rdbms.mapping.java.MultiMapping are in unnamed module of loader 'app')
at org.datanucleus.store.rdbms.mapping.CorrespondentColumnsMapper.(CorrespondentColumnsMapper.java:254)
at org.datanucleus.store.rdbms.mapping.java.PersistableMapping.prepareColumnMapping(PersistableMapping.java:242)
at org.datanucleus.store.rdbms.mapping.java.PersistableMapping.initialize(PersistableMapping.java:130)
at org.datanucleus.store.rdbms.mapping.MappingManagerImpl.getMapping(MappingManagerImpl.java:663)
at org.datanucleus.store.rdbms.table.ClassView.initialize(ClassView.java:135)

The limitation seems to be the ClassView which consider a view does not have an id, which is not always the case. I think having id in view could help with caching, at least to have it optional
dn-view.zip
.

[andyjefferson]

An RDBMS "VIEW" doesn't have a primary key in most treatments of VIEW.