Databases are needed if you want to persist data for a longer period of time, or if data must consistently be accessible from different sessions (different users). This chapter refers to SQL (Structured Query Language) databases. For an introduction, see for example the article at https://en.wikipedia.org/wiki/Database.
JPA (Java Persistence API) is the dedicated technology used to access relational databases from inside Jakarta EE. Its aim is to provide a bridge between SQL tables and Java objects. This task is much more complex than in other basic data schemes. The reason for ...
