Introduction One of my readers asked me to help him map a Composite Primary Key using JPA and Hibernate. Because this is a recurrent question, I decided to write a blog post in which I describe this mapping is more detail. Domain Model A relational database composite key contains two or more columns which together for the primary key of a given table. In the diagram above, the employee table has a Composite Primary Key, which consists of two columns: company_id employee_number Every Employee can also have a Phone, which uses the... Read More