There are two attributes you can put on your entity class properties: one is a convenience, the other is essential, and both are required when the primary key for a table consists of two columns. When ...

One of the principles within relational theory is that each entity’s row or tuple be uniquely identifiable. This means the defined structure includes some combination of attributes whose populated ...

Every JPA entity has a primary key, but some entities have more than one value as their primary key. In this case, you need to use a composite key. This Java tip introduces you to using composite keys ...