From f15ea65c06b19604c30fe26dc22643d4701f7dbb Mon Sep 17 00:00:00 2001
From: Rebwon <msolo021015@naver.com>
Date: Sat, 16 Oct 2021 12:09:26 +0900
Subject: [PATCH] Implements Article Pagination Query

---
 .../yam/app/article/domain/ArticleReader.java |  4 ++++
 .../MybatisArticleRepository.java             |  6 ++++++
 .../mapper/xml/ArticleQueryMapper.xml         | 14 +++++++++++++
 .../article/domain/FakeArticleRepository.java |  6 ++++++
 .../infrastructure/ArticleReaderTest.java     | 21 +++++++++++++++++++
 5 files changed, 51 insertions(+)
 create mode 100644 src/test/java/com/yam/app/article/infrastructure/ArticleReaderTest.java

diff --git a/src/main/java/com/yam/app/article/domain/ArticleReader.java b/src/main/java/com/yam/app/article/domain/ArticleReader.java
index 4e1e304..98a6879 100644
--- a/src/main/java/com/yam/app/article/domain/ArticleReader.java
+++ b/src/main/java/com/yam/app/article/domain/ArticleReader.java
@@ -1,6 +1,8 @@
 package com.yam.app.article.domain;
 
+import java.util.List;
 import java.util.Optional;
+import org.apache.ibatis.annotations.Param;
 
 public interface ArticleReader {
 
@@ -9,4 +11,6 @@ public interface ArticleReader {
     Optional<Article> findById(Long articleId);
 
     boolean existsById(Long articleId);
+
+    List<Long> findAll(@Param("offset") int offset, @Param("limit") int limit);
 }
diff --git a/src/main/java/com/yam/app/article/infrastructure/MybatisArticleRepository.java b/src/main/java/com/yam/app/article/infrastructure/MybatisArticleRepository.java
index 2128103..bd4569b 100644
--- a/src/main/java/com/yam/app/article/infrastructure/MybatisArticleRepository.java
+++ b/src/main/java/com/yam/app/article/infrastructure/MybatisArticleRepository.java
@@ -3,6 +3,7 @@ package com.yam.app.article.infrastructure;
 import com.yam.app.article.domain.Article;
 import com.yam.app.article.domain.ArticleReader;
 import com.yam.app.article.domain.ArticleRepository;
+import java.util.List;
 import java.util.Optional;
 import org.mybatis.spring.SqlSessionTemplate;
 
@@ -40,4 +41,9 @@ public final class MybatisArticleRepository implements ArticleReader, ArticleRep
         return template.getMapper(ArticleReader.class).existsById(articleId);
     }
 
+    @Override
+    public List<Long> findAll(int offset, int limit) {
+        return template.getMapper(ArticleReader.class).findAll(offset, limit);
+    }
+
 }
diff --git a/src/main/resources/mapper/xml/ArticleQueryMapper.xml b/src/main/resources/mapper/xml/ArticleQueryMapper.xml
index 49d96ca..3008999 100644
--- a/src/main/resources/mapper/xml/ArticleQueryMapper.xml
+++ b/src/main/resources/mapper/xml/ArticleQueryMapper.xml
@@ -3,6 +3,20 @@
 
 <mapper namespace="com.yam.app.article.domain.ArticleReader">
 
+  <select id="findAll" resultMap="articleId">
+    SELECT
+    DISTINCT(a.id) AS article_id, a.created_at
+    FROM article a
+    INNER JOIN article_tag atg ON atg.article_id = a.id
+    INNER JOIN tag t ON t.id = atg.tag_id
+    ORDER BY a.created_at DESC
+    LIMIT #{offset}, #{limit}
+  </select>
+
+  <resultMap id="articleId" type="Long">
+    <id javaType="Long" column="article_id"/>
+  </resultMap>
+
   <select id="existsById" parameterType="Long" resultType="boolean">
     SELECT COUNT(*)
     FROM ARTICLE
diff --git a/src/test/java/com/yam/app/article/domain/FakeArticleRepository.java b/src/test/java/com/yam/app/article/domain/FakeArticleRepository.java
index abb4836..2d522b2 100644
--- a/src/test/java/com/yam/app/article/domain/FakeArticleRepository.java
+++ b/src/test/java/com/yam/app/article/domain/FakeArticleRepository.java
@@ -1,5 +1,6 @@
 package com.yam.app.article.domain;
 
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
@@ -35,4 +36,9 @@ public final class FakeArticleRepository implements ArticleRepository, ArticleRe
     public boolean existsById(Long articleId) {
         return data.containsKey(articleId);
     }
+
+    @Override
+    public List<Long> findAll(int offset, int limit) {
+        throw new UnsupportedOperationException();
+    }
 }
diff --git a/src/test/java/com/yam/app/article/infrastructure/ArticleReaderTest.java b/src/test/java/com/yam/app/article/infrastructure/ArticleReaderTest.java
new file mode 100644
index 0000000..3a64c89
--- /dev/null
+++ b/src/test/java/com/yam/app/article/infrastructure/ArticleReaderTest.java
@@ -0,0 +1,21 @@
+package com.yam.app.article.infrastructure;
+
+import com.yam.app.article.domain.ArticleReader;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+@SpringBootTest
+@ActiveProfiles("test")
+public final class ArticleReaderTest {
+
+    @Autowired
+    ArticleReader articleReader;
+
+    @Test
+    void name() {
+        List<Long> idx = articleReader.findAll(0, 10);
+    }
+}