The repository pattern puts database operations in a separate object rather than on the entity itself. In a Quarkus application, Panache supports this approach alongside the active record pattern. Keeping persistence operations outside entity classes can improve separation of concerns and flexibility; the choice of pattern does not determine the database. section 7.2
To use a Panache repository for a MySQL-backed inventory:
- Add the quarkus-hibernate-orm-panache and quarkus-jdbc-mysql extensions, then configure the MySQL datasource. section 7.2.1
- Define an ordinary JPA entity with @Entity and an ID. Unlike an entity extending PanacheEntity, a plain JPA entity declares its own ID field. section 7.2.1
- Create an @ApplicationScoped class implementing PanacheRepository<Car>. It can start empty and gain application-specific query methods as needed. section 7.2.1
Listing 7.14 The code of the CarRepository class
package org.acme.inventory.repository;
import io.quarkus.hibernate.orm.panache.PanacheRepository;
import jakarta.enterprise.context.ApplicationScoped;
import org.acme.inventory.model.Car;
@ApplicationScoped
public class CarRepository implements PanacheRepository<Car> {
}
The minimal repository declaration shows where Panache’s database operations become available without putting them on the Car entity. section 7.2.1
Find a car by license plate
Add findByLicensePlateNumberOptional to the repository. It calls find("licensePlateNumber", licensePlateNumber).firstResultOptional(), letting a caller request one matching car rather than list every car and filter manually. section 7.2.1 section 7.2.2
Inject the repository into the GraphQL and gRPC inventory services in place of the in-memory stub. Call listAll to read cars, persist to register one, and the custom lookup followed by delete to remove one. Database-changing GraphQL methods use @Transactional; the gRPC persistence callback instead starts a transaction with QuarkusTransaction.requiringNew(). section 7.2.2
For development or testing, src/main/resources/import.sql can load initial cars when Quarkus connects; this import is disabled in production mode by default. The pattern is not limited to MySQL: Panache also offers MongoDB repository interfaces, although the MongoDB rental example uses active record instead. section 7.2.2 section 7.6.1
