There appears to be a bug in @NamedEntityGraph when trying to eager load a @OnetoOne mapping with @Mapsid in a Single Table inheritance setup.

When doing eager loading, I get the following error:

Caused by: org.postgresql.util.PSQLException: ERROR: operator does not exist: uuid = character varying Hint: No operator matches the given name and argument types. You might need to add explicit type casts.

Generated sql:
'select p1_0.id,d1_0.parent_id,d1_0.dtype,d1_0.organization_id,d1_0.module_width,p1_0.organization_id from physical_aspect p1_0 left join physical_aspect_definition d1_0 on p1_0.id=d1_0.dtype where p1_0.organization_id=?'

Seems like trying to compare id=dtype (discriminator column).

The bug appears in Hibernate 6.1.3 and previous versions og 6.

The @NamedEntityGraph feature is tested working with Hibernate 5.6.11

I've included a testcase for both 6.1.3 and 5.6.11.
-> See EagerLoadingEntityGraphTest#testEagerloadingByNamedEntityGraphAnnotationFails()