Spring Data JPA Pagination, Querydsl의 pagenation연결

1. 스프링 데이터의 Page, Pageable을 활용

 // List<MemberTeamDto> search(MemberSerarchCondition condition); 커스텀하게 이런 쿼리 만들 때
 
public interface MemberRepositoryCustom {
    List<MemberTeamDto> search(MemberSerarchCondition condition);
    Page<MemberTeamDto> searchPageSimple(MemberSerarchCondition condition, Pageable, pageable);
    Page<MemberTeamDto> searchPageComplex(MemberSerarchCondition condition, Pageable, pageable);
    
}

 

2. 전체 카운트를 한번에 조회하는 단순한 방법

fetchReult를 통해서 컨텐츠용, 페이징용 두 개 쿼리 날림

 

@Override
public Page<MemberTeamDto> searchPageSimple(MemberSearchCondition condition,
Pageable pageable) {

 		QueryResults<MemberTeamDto> results = queryFactory
 			.select(new QMemberTeamDto(
 					member.id,
 					member.username,
 					member.age,
 					team.id,
 					team.name))
 				.from(member)
 				.leftJoin(member.team, team)
 				.where(usernameEq(condition.getUsername()),
 						teamNameEq(condition.getTeamName()),
 						ageGoe(condition.getAgeGoe()),
 						ageLoe(condition.getAgeLoe()))
 					.offset(pageable.getOffset())
 					.limit(pageable.getPageSize())
 					.fetchResults();
 
 	List<MemberTeamDto> content = results.getResults();
 	long total = results.getTotal();
    
 	return new PageImpl<>(content, pageable, total);
}

 

3. 데이터 내용과 전체 카운트를 별도로 조회하는 방법

이건 leftJoin이나 특정한 상황에서 content 쿼리는 복잡해도 카운트 쿼리는 단순한 경우 있을 수 있다. 이럴 때 사용

@Override
public Page<MemberTeamDto> searchPageComplex(MemberSearchCondition condition,
Pageable pageable) {
 				List<MemberTeamDto> content = queryFactory
					 .select(new QMemberTeamDto(
 								member.id,
								member.username,
 								member.age,
 								team.id,
 								team.name))
 					.from(member)
 					.leftJoin(member.team, team)
 					.where(usernameEq(condition.getUsername()),
 						teamNameEq(condition.getTeamName()),
 						ageGoe(condition.getAgeGoe()),
 						ageLoe(condition.getAgeLoe()))
 					.offset(pageable.getOffset())
 					.limit(pageable.getPageSize())
 					.fetch();
 				long total = queryFactory
 					.select(member)
 					.from(member)
 					.leftJoin(member.team, team)
 					.where(usernameEq(condition.getUsername()),
 					teamNameEq(condition.getTeamName()),
 					ageGoe(condition.getAgeGoe()),
 					ageLoe(condition.getAgeLoe()))
					.fetchCount();
 				return new PageImpl<>(content, pageable, total);
}

4. CountQuery 최적화

강의노트 참고

 

https://devlog-wjdrbs96.tistory.com/414

[Spring] Spring Data JPA에서 Paging 간단하게 구현하는 법