[TIL] 20240226 Spring JPA Query method

1. @query 이용

Java Persistence Query Language 인 JPQL이용

Repository method에  @Query Annotation을 사용해서 위의 과정을 SpringDataJPA에 위임

 파라미터가 3개 이상이 되거나 order by 절 등을 사용해서 쿼리가 복잡해지면 메서드명이 엄청나게 늘어나 가독성을 저하될때 사용

public interface UserRepository extends JpaRepository<User, Long> {
  @Query("select u from User u where u.emailAddress = ?1")
  User findByEmailAddress(String emailAddress);
}

 

2. query method 이용

메서드를 만들어 쓰는 방식을 통해서 서비스단에서 그 메서드를 이용하면, 스스로 쿼리를 생성하여 작동

Keyword	Sample	JPQL snippet
Distinct	findDistinctByLastnameAndFirstname	select distinct …​ where x.lastname = ?1 and x.firstname = ?2
And	findByLastnameAndFirstname	… where x.lastname = ?1 and x.firstname = ?2
Or	findByLastnameOrFirstname	… where x.lastname = ?1 or x.firstname = ?2
Is, Equals	findByFirstname,findByFirstnameIs,findByFirstnameEquals	… where x.firstname = ?1
Between	findByStartDateBetween	… where x.startDate between ?1 and ?2
LessThan	findByAgeLessThan	… where x.age < ?1
LessThanEqual	findByAgeLessThanEqual	… where x.age <= ?1
GreaterThan	findByAgeGreaterThan	… where x.age > ?1
GreaterThanEqual	findByAgeGreaterThanEqual	… where x.age >= ?1
After	findByStartDateAfter	… where x.startDate > ?1
Before	findByStartDateBefore	… where x.startDate < ?1
IsNull, Null	findByAge(Is)Null	… 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> ages)	… where x.age not in ?1
True	findByActiveTrue()	… where x.active = true
False	findByActiveFalse()	… where x.active = false
IgnoreCase	findByFirstnameIgnoreCase	… where UPPER(x.firstname) = UPPER(?1)

 

3. 주의사항

필요한 부분만 꺼내쓰는 것이 중요

성능이슈)

• Hibernate 캐시에 복사본 저장
• 불필요한 컬럼 조회
• OneToOne에서의 N+1 쿼리