Is ORM the only way to implement Java Persistence API, or are there alternative approaches?

ORM (Object-Relational Mapping) is the most common way to implement Java Persistence API (JPA), but not the only one. JPA is a specification that describes how to work with persistent data in Java, and ORM is one of the possible implementations of this specification.

Alternative approaches:

• JDBC (Java Database Connectivity) — a low-level API for working with databases without ORM, with manual management of SQL queries.
• Native SQL — using native SQL queries through EntityManager or JDBC.
• NoSQL solutions — if the data is non-relational, other approaches not related to ORM can be used.

Thus, ORM is a convenient and popular method, but JPA also allows other ways to work with data.