Hello, I just wrote a new post about JPA: Mini Book - First Steps and detailed concepts
There is a lot of material to those who is starting and concepts that seniors might want to take a look.
I hope you guys like it. [=
Page 02: Reasons that led to the creation of JPA
Page 03: What is JPA? What is a JPA Implementation?
Page 04: What is the persistence.xml file used for? And its configurations?
Page 05: Entity definitions. What are the Logic and Physical annotations?
Page 06: Id Generation: Definition, using Identity or Sequence
Page 07: Id Generation: TableGenerator and Auto
Page 08: Simple Composite Key
Page 09: Complex Composite Key
Page 10: How to get an EntityManager
Page 11: Mapping two or more tables in one entity
Page 12: Mapping Hierarchy: MappedSuperclass
Page 13: Mapping Hierarchy: Single Table
Page 14: Mapping Hierarchy: Joined
Page 15: Mapping Hierarchy: Table per Concrete Class
Page 16: Pros/Cons of each hierarchy mapping approach
Page 17: Embedded Objects
Page 18: ElementCollection – how to map a list of values into a class
Page 19: OneToOne unidirectional and bidirectional
Page 20: OneToMany/ManyToOne unidirectional and bidirectional
Page 21: ManyToMany unidirectional and bidirectional
Page 22: ManyToMany with extra fields
Page 23: How the Cascade functionality works? How should a developer use the OrphanRemoval? Handling the org.hibernate.TransientObjectException
Page 24: How to delete an entity with relationships. How to know which relationships are raising the exception
Page 25: Creating one EntityManagerFactory by application
Page 26: Understanding how the Lazy/Eager option works
Page 27: Handling the “cannot simultaneously fetch multiple bags” error