Definition:
Jakarta Query (formerly JPA Criteria API) is a Java specification that allows developers to build database queries programmatically using Java code instead of writing SQL strings. It provides a type-safe, object-oriented way to construct dynamic queries at runtime.
Key Features
- Type-safe: Compile-time checking prevents SQL errors
- Dynamic: Build queries conditionally based on user input
- Database-agnostic: Works across different database systems
- IDE-friendly: Auto-completion and refactoring support
Example:
Traditional SQL String:
String sql = "SELECT p FROM Person p WHERE p.age > 25 AND p.city = 'New York'";Jakarta Query (Criteria API):
CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery<Person> query = cb.createQuery(Person.class);
Root<Person> person = query.from(Person.class);
query.select(person)
.where(cb.and(
cb.greaterThan(person.get("age"), 25),
cb.equal(person.get("city"), "New York")
));
List<Person> results = entityManager.createQuery(query).getResultList();