week3 과제

seojin/week3.md

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+## 검색 API
+
+### 연관된 테이블
+
+- 리포트(통계)
+- 스크랩 여부 (Scrap)
+- 부동산 가격 정보(LimjangPrice)
+- 이미지(Image)
+
+### `containsIgnoreCase`
+
+- 이 메소드 쓰면 자동으로 Lower로 바꾸어주고, 입력한 값 양 옆에 %를 붙여준다.
+- 소문자로 변환할 필요없으면 그냥 `contains` 써주어도 된다.
+
+## `keywordOf`
+
+- 인자로 전해진 removeBlank() 메소드들 사이에 하나라도 참이라면(nickname, address, addressDetail 컬럼 중 하나라도 키워드가 포함된다면) 해당 데이터 반환
+
+## `removeBlank`
+
+- Expressions.stringTemplate으로 컬럼 공백제거
+
+```java
+ @Override
+  public List<Limjang> searchLimjangs(Member member, String keyword) {
+    String rKeyword = keyword.replaceAll(" ", "");
+
+    return queryFactory
+        .selectFrom(limjang)
+        .leftJoin(limjang.report, report).fetchJoin()
+        .leftJoin(limjang.scrap, scrap).fetchJoin()
+        .leftJoin(limjang.priceId, limjangPrice).fetchJoin()
+        .leftJoin(limjang.imageList, image).fetchJoin()
+        .where(limjang.memberId.eq(member),
+            keywordOf(
+                removeBlank(limjang.nickname).containsIgnoreCase(rKeyword),
+                removeBlank(limjang.address).containsIgnoreCase(rKeyword),
+                removeBlank(limjang.addressDetail).containsIgnoreCase(rKeyword)
+            ))
+        .fetch();
+  }
+
+  private BooleanExpression keywordOf(BooleanExpression... conditions) {
+    BooleanExpression result = null;
+    for (BooleanExpression condition : conditions) {
+      result = result == null ? condition : result.or(condition);
+    }
+    return result;
+  }
+
+  private StringExpression removeBlank(StringExpression origin) {
+    return Expressions.stringTemplate("function('replace', {0}, ' ', '')", origin);
+  }
+```
+
+### 쿼리
+
+```sql
+select
+    l1_0.limjang_id,
+    l1_0.address,
+    l1_0.address_detail,
+    l1_0.created_at,
+    l1_0.deleted,
+    il1_0.limjang_id,
+    il1_0.image_id,
+    il1_0.created_at,
+    il1_0.image_url,
+    il1_0.updated_at,
+    l1_0.member_id,
+    l1_0.memo,
+    l1_0.nickname,
+    pi1_0.price_id,
+    pi1_0.created_at,
+    pi1_0.deposit_price,
+    pi1_0.market_price,
+    pi1_0.monthly_rent,
+    pi1_0.pull_rent,
+    pi1_0.selling_price,
+    pi1_0.updated_at,
+    l1_0.price_type,
+    l1_0.property_type,
+    l1_0.purpose,
+    l1_0.record_count,
+    r1_0.report_id,
+    r1_0.created_at,
+    r1_0.indoor_keyword,
+    r1_0.indoor_rate,
+    r1_0.location_conditions_keyword,
+    r1_0.location_conditions_rate,
+    r1_0.public_space_keyword,
+    r1_0.public_space_rate,
+    r1_0.total_rate,
+    r1_0.updated_at,
+    s1_0.scrap_id,
+    s1_0.created_at,
+    s1_0.updated_at,
+    l1_0.updated_at
+from
+    limjang l1_0
+left join
+    report r1_0
+        on l1_0.limjang_id=r1_0.limjang_id
+left join
+    scrap s1_0
+        on l1_0.limjang_id=s1_0.limjang_id
+left join
+    limjang_price pi1_0
+        on pi1_0.price_id=l1_0.price_id
+left join
+    image il1_0
+        on l1_0.limjang_id=il1_0.limjang_id
+where
+    (
+        l1_0.deleted = false
+    )
+    and l1_0.member_id=?
+    and (
+        lower(replace(l1_0.nickname, ' ', '')) like ? escape '!'
+        or lower(replace(l1_0.address, ' ', '')) like ? escape '!'
+        or lower(replace(l1_0.address_detail, ' ', '')) like ? escape '!'
+    )
+
+```
+```
+
+## 메인화면 API
+
+연관된 테이블 
+
+- 리포트(통계)
+- 스크랩 여부 (Scrap)
+- 부동산 가격 정보(LimjangPrice)
+- 이미지(Image)
+
+```java
+  @Override
+  public List<Limjang> findMainScreenContentsLimjang(Member member) {
+
+    return queryFactory
+        .selectFrom(limjang)
+        .leftJoin(limjang.report, report).fetchJoin()
+        .leftJoin(limjang.scrap, scrap).fetchJoin()
+        .leftJoin(limjang.priceId, limjangPrice).fetchJoin()
+        .leftJoin(limjang.imageList, image).fetchJoin()
+        .where(limjang.memberId.eq(member))
+        .orderBy(limjang.updatedAt.desc())
+        .limit(5)
+        .fetch();
+  }
+```
+
+### 쿼리
+
+```sql
+    select
+        l1_0.limjang_id,
+        l1_0.address,
+        l1_0.address_detail,
+        l1_0.created_at,
+        l1_0.deleted,
+        il1_0.limjang_id,
+        il1_0.image_id,
+        il1_0.created_at,
+        il1_0.image_url,
+        il1_0.updated_at,
+        l1_0.member_id,
+        l1_0.memo,
+        l1_0.nickname,
+        pi1_0.price_id,
+        pi1_0.created_at,
+        pi1_0.deposit_price,
+        pi1_0.market_price,
+        pi1_0.monthly_rent,
+        pi1_0.pull_rent,
+        pi1_0.selling_price,
+        pi1_0.updated_at,
+        l1_0.price_type,
+        l1_0.property_type,
+        l1_0.purpose,
+        l1_0.record_count,
+        r1_0.report_id,
+        r1_0.created_at,
+        r1_0.indoor_keyword,
+        r1_0.indoor_rate,
+        r1_0.location_conditions_keyword,
+        r1_0.location_conditions_rate,
+        r1_0.public_space_keyword,
+        r1_0.public_space_rate,
+        r1_0.total_rate,
+        r1_0.updated_at,
+        s1_0.scrap_id,
+        s1_0.created_at,
+        s1_0.updated_at,
+        l1_0.updated_at 
+    from
+        limjang l1_0 
+    left join
+        report r1_0 
+            on l1_0.limjang_id=r1_0.limjang_id 
+    left join
+        scrap s1_0 
+            on l1_0.limjang_id=s1_0.limjang_id 
+    left join
+        limjang_price pi1_0 
+            on pi1_0.price_id=l1_0.price_id 
+    left join
+        image il1_0 
+            on l1_0.limjang_id=il1_0.limjang_id 
+    where
+        (
+            l1_0.deleted = false
+        ) 
+        and l1_0.member_id=? 
+    order by
+        l1_0.updated_at desc
+```
+
+## 고민한거
+
+- 쿼리 나갈 때 대상 테이블과 조인된 모든 테이블의 컬럼이 다 조회되는데 이게 맞는지 → 보통 역할이 리포지토리에서 엔티티 조회하고, 서비스 계층에서 DTO로 가공해주니까
+- 김영한님 최적화 내용 보니까 엔티티로 모두 조회하나 DTO로 일부 컬럼만 조회하나 사실 성능상 별로 차이는 없다함
+- **[수십억건에서 QUERYDSL 사용하기](https://youtu.be/zMAX7g6rO_Y?si=AP42XASlT3aJuT8n)** 영상에서 보니까 대용량 데이터 처리할 때는 DTO로 조회하는 것을 권장한다고 합니다 (영상 내용 유익해서 한번 보면 좋을 듯)