Win a copy of JDBC Workbook this week in the JDBC and Relational Databases forum
or A Day in Code in the A Day in Code forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums
this forum made possible by our volunteer staff, including ...
  • Campbell Ritchie
  • Paul Clapham
  • Jeanne Boyarsky
  • Junilu Lacar
  • Henry Wong
  • Ron McLeod
  • Devaka Cooray
  • Tim Cooke
Saloon Keepers:
  • Tim Moores
  • Stephan van Hulst
  • Frits Walraven
  • Tim Holloway
  • Carey Brown
  • Piet Souris
  • salvin francis
  • fred rosenberger

My exam cloud mock 4, primary key class

Ranch Foreman
Posts: 1897
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

The Java Persistence entity UserRole defines a composite primary key that is defined by the two columns userID and RoleID in the DB.
Which two are true?
Choose two.
A. UserRole must define a primary key class to represent the composite primary key.
B. The composite primary key is mapped as two fields in UserRole. No extra primary key class is necessary.
C. The combination of @Embedded and @Embeddable annotations can be used to denote the composite primary key.
D. The semantics of the equals and hashCode methods of the primary key class must be consist with the database equality.
Given answers :A,D.

I think the answers should be A,B,D.
For example, the two id's field should be mapped to the columns
Creator of Enthuware JWS+ V6
Posts: 3341
Android Eclipse IDE Chrome
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
B is not correct because you need an extra primary key class (the one you are showing: @IdClass(Id.class))
You can't expect to wield supreme executive power just because
Devious Experiments for a Truly Passive Greenhouse!
    Bookmark Topic Watch Topic
  • New Topic