6주차

섹션 6. 네 번째 요구사항 추가하기 - Querydsl

섹션 7. 마지막 섹션

최종 결과물 

https://github.com/hagisilm/Kotlin-basic

 

https://www.inflearn.com/course/java-to-kotlin-2/dashboard

실전! 코틀린과 스프링 부트로 도서관리 애플리케이션 개발하기 (Java 프로젝트 리팩토링) - 인프

user querydsl(custom,impl)

package com.group.libraryapp.domain.user

interface UserRepositoryCustom {
    fun findAllWithHistories(): List<User>
}

package com.group.libraryapp.domain.user

import com.group.libraryapp.domain.user.QUser.user
import com.group.libraryapp.domain.user.loanhistory.QUserLoanHistory.userLoanHistory
import com.querydsl.jpa.impl.JPAQueryFactory

class UserRepositoryCustomImpl(
    private val queryFactory: JPAQueryFactory
) : UserRepositoryCustom {

    override fun findAllWithHistories(): List<User> {
        return queryFactory.select(user).distinct()
            .from(user)
            .leftJoin(userLoanHistory).on(userLoanHistory.user.id.eq(user.id)).fetchJoin()
            .fetch()
    }
}

 

book(다른 방식)

package com.group.libraryapp.repository.book

import com.group.libraryapp.domain.book.QBook.book
import com.group.libraryapp.dto.book.response.BookStatResponse
import com.querydsl.core.QueryFactory
import com.querydsl.core.types.Projections
import com.querydsl.jpa.impl.JPAQueryFactory
import org.hibernate.criterion.Projection
import org.springframework.data.jpa.repository.JpaRepository
import org.springframework.stereotype.Component

@Component
class BookQuerydslRepository(
    private val queryFactory: JPAQueryFactory,
) {
    fun getStats(): List<BookStatResponse> {
        return queryFactory.select(
            Projections.constructor(
                BookStatResponse::class.java,
                book.type,
            )
        )
            .from(book)

            .groupBy(book.type)
            .fetch()
    }
}

user (querydsl)

package com.group.libraryapp.repository.user.loanhistory

import com.group.libraryapp.domain.user.loanhistory.QUserLoanHistory.userLoanHistory
import com.group.libraryapp.domain.user.loanhistory.UserLoanHistory
import com.group.libraryapp.domain.user.loanhistory.UserLoanStatus
import com.querydsl.core.QueryFactory
import com.querydsl.jpa.impl.JPAQueryFactory
import org.springframework.stereotype.Component

@Component
class UserLoanHistoryQuerydslRepository(
    private val queryFactory: JPAQueryFactory
) {
    fun find(bookName: String, status: UserLoanStatus? = null): UserLoanHistory? {
         return queryFactory.select(userLoanHistory)
            .from(userLoanHistory)
            .where(
                userLoanHistory.bookName.eq(bookName),
                status?.let { userLoanHistory.status.eq(status) }
            )
            .limit(1)
            .fetchOne()
    }

    fun count(status: UserLoanStatus): Long{
        return queryFactory.select(userLoanHistory.id.count())
            .from(userLoanHistory)
            .where(
                userLoanHistory.status.eq(status)
            )
            .fetchOne()?: 0L
    }
}