카테고리 별 템플릿 개수 조회 (#1031)

woowacourse-teams · Feb 23, 2025 · 4e2d561 · 4e2d561
1 parent 76ef3f4
commit 4e2d561
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Showing 8 changed files with 120 additions and 11 deletions.
diff --git a/backend/src/main/java/codezap/category/domain/Category.java b/backend/src/main/java/codezap/category/domain/Category.java
@@ -11,6 +11,9 @@
 import jakarta.persistence.Table;
 import jakarta.persistence.UniqueConstraint;
 
+import org.hibernate.annotations.ColumnDefault;
+import org.hibernate.annotations.DynamicUpdate;
+
 import codezap.global.auditing.BaseTimeEntity;
 import codezap.member.domain.Member;
 import lombok.AccessLevel;
@@ -20,6 +23,7 @@
 import lombok.NoArgsConstructor;
 
 @Entity
+@DynamicUpdate
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 @AllArgsConstructor
 @Table(
@@ -36,6 +40,7 @@
 public class Category extends BaseTimeEntity {
 
     private static final String DEFAULT_CATEGORY_NAME = "카테고리 없음";
+    private static final long DEFAULT_TEMPLATE_COUNT = 0L;
     private static final int DEFAULT_CATEGORY_ORDINAL = 0;
 
     @Id
@@ -54,12 +59,17 @@ public class Category extends BaseTimeEntity {
     @Column(nullable = false)
     private int ordinal;
 
+    @Column
+    @ColumnDefault("0")
+    private long templateCount;
+
+
     public Category(String name, Member member, int ordinal) {
-        this(null, member, name, false, ordinal);
+        this(null, member, name, false, ordinal, DEFAULT_TEMPLATE_COUNT);
     }
 
     public static Category createDefaultCategory(Member member) {
-        return new Category(null, member, DEFAULT_CATEGORY_NAME, true, DEFAULT_CATEGORY_ORDINAL);
+        return new Category(null, member, DEFAULT_CATEGORY_NAME, true, DEFAULT_CATEGORY_ORDINAL, DEFAULT_TEMPLATE_COUNT);
     }
 
     public boolean hasAuthorization(Member member) {
@@ -74,4 +84,15 @@ public void update(String name, int ordinal) {
         this.name = name;
         this.ordinal = ordinal;
     }
+
+    public void increaseTemplateCount() {
+        this.templateCount++;
+    }
+
+    public void decreaseTemplateCount() {
+        if (this.templateCount <= DEFAULT_TEMPLATE_COUNT) {
+            return;
+        }
+        this.templateCount--;
+    }
 }
diff --git a/backend/src/main/java/codezap/category/dto/response/FindCategoryResponse.java b/backend/src/main/java/codezap/category/dto/response/FindCategoryResponse.java
@@ -9,9 +9,11 @@ public record FindCategoryResponse(
         @Schema(description = "카테고리 이름", example = "Spring")
         String name,
         @Schema(description = "카테고리 순서", example = "1")
-        long ordinal
+        int ordinal,
+        @Schema(description = "카테고리 개수", example = "1")
+        long count
 ) {
     public static FindCategoryResponse from(Category category) {
-        return new FindCategoryResponse(category.getId(), category.getName(), category.getOrdinal());
+        return new FindCategoryResponse(category.getId(), category.getName(), category.getOrdinal(), category.getTemplateCount());
     }
 }
diff --git a/backend/src/main/java/codezap/template/service/TemplateService.java b/backend/src/main/java/codezap/template/service/TemplateService.java
@@ -64,9 +64,8 @@ public Template update(
             Category category
     ) {
         Template template = templateRepository.fetchById(templateId);
-        if (!template.matchMember(member)) {
-            throw new CodeZapException(ErrorCode.FORBIDDEN_ACCESS, "해당 템플릿에 대한 권한이 없습니다.");
-        }
+        validateAuthorization(member, template);
+        updateTemplateCount(category, template);
         template.updateTemplate(
                 request.title(),
                 request.description(),
@@ -76,6 +75,15 @@ public Template update(
         return template;
     }
 
+    private void updateTemplateCount(Category changedCategory, Template template) {
+        Category originalCategory = template.getCategory();
+        if (originalCategory.equals(changedCategory)) {
+            return;
+        }
+        originalCategory.decreaseTemplateCount();
+        changedCategory.increaseTemplateCount();
+    }
+
     @Transactional
     public void deleteByMemberAndIds(Member member, List<Long> ids) {
         if (ids.size() != new HashSet<>(ids).size()) {
@@ -86,9 +94,15 @@ public void deleteByMemberAndIds(Member member, List<Long> ids) {
 
     private void deleteById(Member member, Long id) {
         Template template = templateRepository.fetchById(id);
+        validateAuthorization(member, template);
+        Category category = template.getCategory();
+        category.decreaseTemplateCount();
+        templateRepository.deleteById(id);
+    }
+
+    private void validateAuthorization(Member member, Template template) {
         if (!template.matchMember(member)) {
             throw new CodeZapException(ErrorCode.FORBIDDEN_ACCESS, "해당 템플릿에 대한 권한이 없습니다.");
         }
-        templateRepository.deleteById(id);
     }
 }
diff --git a/backend/src/main/resources/db/migration/V10__category_column_denormalization.sql b/backend/src/main/resources/db/migration/V10__category_column_denormalization.sql
@@ -0,0 +1,8 @@
+ALTER TABLE category ADD COLUMN template_count BIGINT DEFAULT 0;
+
+UPDATE category c
+SET template_count = (
+    SELECT COUNT(1)
+    FROM template t
+    WHERE t.category_id = c.id
+);
diff --git a/backend/src/main/resources/db/migration/V14__category_column_denormalization.sql b/backend/src/main/resources/db/migration/V14__category_column_denormalization.sql
@@ -0,0 +1,8 @@
+ALTER TABLE category ADD COLUMN template_count BIGINT DEFAULT 0;
+
+UPDATE category c
+SET template_count = (
+    SELECT COUNT(1)
+    FROM template t
+    WHERE t.category_id = c.id
+);
diff --git a/backend/src/test/java/codezap/category/domain/CategoryTest.java b/backend/src/test/java/codezap/category/domain/CategoryTest.java
@@ -0,0 +1,56 @@
+package codezap.category.domain;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import codezap.fixture.CategoryFixture;
+import codezap.fixture.MemberFixture;
+import codezap.member.domain.Member;
+
+public class CategoryTest {
+
+    @Nested
+    @DisplayName("템플릿 개수 증가 성공")
+    class IncreaseTemplateCount {
+
+        @Test
+        @DisplayName("템플릿 개수 증가 성공")
+        void increaseTemplateCountSuccess() {
+            Category category = CategoryFixture.getDefaultCategory(MemberFixture.getFirstMember());
+
+            category.increaseTemplateCount();
+
+            assertThat(category.getTemplateCount()).isEqualTo(1);
+        }
+    }
+
+    @Nested
+    @DisplayName("템플릿 개수 감소 성공")
+    class DecreaseTemplateCount {
+
+        @Test
+        @DisplayName("템플릿 개수 감소 성공")
+        void decreaseTemplateCountSuccess() {
+            Category category = CategoryFixture.getDefaultCategory(MemberFixture.getFirstMember());
+
+            category.increaseTemplateCount();
+            category.increaseTemplateCount();
+            category.decreaseTemplateCount();
+
+            assertThat(category.getTemplateCount()).isEqualTo(1);
+        }
+
+        @Test
+        @DisplayName("템플릿 개수 감소 성공: 이미 0개인 경우에도 성공")
+        void decreaseTemplateCountSuccessAlreadyZero() {
+            Category category = CategoryFixture.getDefaultCategory(MemberFixture.getFirstMember());
+
+            category.decreaseTemplateCount();
+
+            assertThat(category.getTemplateCount()).isEqualTo(0);
+        }
+    }
+}
diff --git a/backend/src/test/java/codezap/fixture/CategoryFixture.java b/backend/src/test/java/codezap/fixture/CategoryFixture.java
@@ -9,11 +9,11 @@
 
 public class CategoryFixture {
     public static Category getDefaultCategory(Member member) {
-        return new Category(1L, member, "카테고리 없음", true, 1);
+        return new Category(1L, member, "카테고리 없음", true, 1, 0);
     }
 
     public static Category getAdditionalCategory(Member member) {
-        return new Category(2L, member, "카테고리", false, 2);
+        return new Category(2L, member, "카테고리", false, 2, 0);
     }
 
     public static List<Category> getList(Member member, int size) {

diff --git a/backend/submodules/private b/backend/submodules/private