JPA 모듈은 문자열로 쿼리를 정의하거나 메서드에서 파생되어진 쿼리를 사용하는 방법을 지원한다.
스트링으로 쿼리를 정의하는 예시 :
public interface UserRepository extends Repository<User, Long> { List<User> findByEmailAddressAndLastname(String emailAddress, String lastname);
JPA표준 API는 위의 스트링으로 정의된 쿼리를 다음 쿼리로 변경한다.
select u from User u where u.emailAddress = ?1 and u.lastname = ?2
| Keyword | Sample | JPQL snippet |
|---|---|---|
And | findByLastnameAndFirstname | … where x.lastname = ?1 and x.firstname = ?2 |
Or | findByLastnameOrFirstname | … where x.lastname = ?1 or x.firstname = ?2 |
Between | findByStartDateBetween | … where x.startDate between 1? and ?2 |
LessThan | findByAgeLessThan | … where x.age < ?1 |
GreaterThan | findByAgeGreaterThan | … where x.age > ?1 |
After | findByStartDateAfter | … where x.startDate > ?1 |
Before | findByStartDateBefore | … where x.startDate < ?1 |
IsNull | findByAgeIsNull | … where x.age is null |
IsNotNull,NotNull | findByAge(Is)NotNull | … where x.age not null |
Like | findByFirstnameLike | … where x.firstname like ?1 |
NotLike | findByFirstnameNotLike | … where x.firstname not like ?1 |
StartingWith | findByFirstnameStartingWith | … where x.firstname like ?1 (parameter bound with appended %) |
EndingWith | findByFirstnameEndingWith | … where x.firstname like ?1 (parameter bound with prepended %) |
Containing | findByFirstnameContaining | … where x.firstname like ?1 (parameter bound wrapped in %) |
OrderBy | findByAgeOrderByLastnameDesc | … where x.age = ?1 order by x.lastname desc |
Not | findByLastnameNot | … where x.lastname <> ?1 |
In | findByAgeIn(Collection<Age> ages) | … where x.age in ?1 |
NotIn | findByAgeNotIn(Collection<Age> age) | … where x.age not in ?1 |
True | findByActiveTrue() | … where x.active = true |
False | findByActiveFalse() | … where x.active = false |
Using named queries to declare queries for entities is a valid approach and works fine for a small number of queries. As the queries themselves are tied to the Java method that executes them you actually can bind them directly using the Spring Data JPA @Query annotation rather than annotating them to the domain class. This will free the domain class from persistence specific information and co-locate the query to the repository interface.
쿼리메서드에 정의된 쿼리들은 xml에 선언된 @NamedQuery나 named queries보다 우선하여 처리됩니다.
@Query를 이용한 쿼리 선언 예제 :
public interface UserRepository extends JpaRepository<User, Long> { @Query("select u from User u where u.emailAddress = ?1") User findByEmailAddress(String emailAddress); }
By default Spring Data JPA will use position based parameter binding as described in all the samples above. This makes query methods a little error prone to refactoring regarding the parameter position. To solve this issue you can use @Param annotation to give a method parameter a concrete name and bind the name in the query: 기본적으로 스프링 데이터 JPA는 위의 모든 샘플에 설명 된대로 파라미터가 바인딩 된 바인딩 위치 기반 매개 변수를 사용합니다. 파라미터를 이용한 쿼리 선언 예제 :
public interface UserRepository extends JpaRepository<User, Long> { @Query("select u from User u where u.firstname = :firstname or u.lastname = :lastname") User findByLastnameOrFirstname(@Param("lastname") String lastname, @Param("firstname") String firstname); }