Spring Data JPA yana cire boilerplate na rubuta DAO classes. Kana bayyana wani repository interface; a farawa Spring yana samar da proxy implementation da JPA/Hibernate ke goyawa. Ba ka taɓa rubuta entityManager.persist(...) don CRUD na asali.
{
Long id;
String email;
active;
}
<User, Long> {
Optional<User> ;
List<User> ;
}
Derived queries suna da sauƙin karantawa don sharaɗai masu sauƙi amma suna fashewa a tsawo yayin da sharaɗai ke ƙaruwa. Lokacin da haka ta faru, sauka zuwa @Query bayyananne:
@Query("SELECT u FROM User u WHERE u.email = :email") // JPQL, not SQL
Optional<User> lookup(@Param("email") String email);
// Native SQL when you need DB-specific features:
@Query(value = "SELECT * FROM users WHERE active = true", nativeQuery = true)
List<User> findActiveNative();
Page<User> findByActiveTrue(Pageable pageable); // pass PageRequest.of(0, 20)
Masu tambayoyin hira suna bincike ko ka fahimci abin da ake samarwa bayan interface. Ƙarfafan alamu: sanin kalmomin derived-query, zaɓar @Query lokacin da sunayen hanya suka yi wahala, amfani da Pageable maimakon lodin cikakken tebur, da sanin cewa lazy associations na iya haddasa matsalar N+1 — batu da sukan tura zuwa na gaba.
Ɗakin karatu na tambayoyin hira na IT tare da amsoshi cikakke — daga Junior zuwa Senior.
Ba da Gudummawa