JPA 1.0 Mapping I (Java EE 5)


  • Entity Relationships 
  • Directionality 
  • Cardinality 
  • Inheritance (will be covered in “JPA Mapping II”)

Entity Relationships

Aspects of Entity Relationships 

  • Directionality 
    • Uni-directional 
    • Bi-directional
  • Cardinality relationships 
    • One to one 
    • One to many 
    • Many to many 
  • Inheritance relationship 
    • Single-table 
    • Joined-table

Entity Relationships: Java vs. Table 

  • Relationship between entities in Java code is normal object relationship 
  • Relationship among tables can be represented in two forms 
    • Join table 
    • Foreign key 
  • You can control how the object relationship between Java objects can be mapped into tables through JPA annotations


Download course content