🐛 Fix #12859

src/main/java/org/b3log/solo/service/ArticleQueryService.java

@@ -193,10 +193,10 @@ public class ArticleQueryService {
                 tagIds.add(categoryTags.optJSONObject(i).optString(Tag.TAG + "_" + Keys.OBJECT_ID));
             }
 
-            final StringBuilder queryCount = new StringBuilder("SELECT count(0) as C FROM ");
-            final StringBuilder queryList = new StringBuilder("SELECT " + "b3_solo_article.oId ").append(" FROM ");
-            final StringBuilder queryStr = new StringBuilder(articleRepository.getName() + " b3_solo_article,").
-                    append(tagArticleRepository.getName() + " b3_solo_tag_article").
+            final StringBuilder queryCount = new StringBuilder("SELECT count(DISTINCT(b3_solo_article.oId)) as C FROM ");
+            final StringBuilder queryList = new StringBuilder("SELECT DISTINCT(b3_solo_article.oId) ").append(" FROM ");
+            final StringBuilder queryStr = new StringBuilder(articleRepository.getName() + " AS b3_solo_article,").
+                    append(tagArticleRepository.getName() + " AS b3_solo_tag_article").
                     append(" WHERE b3_solo_article.oId=b3_solo_tag_article.article_oId ").
                     append(" AND b3_solo_article.").append(Article.ARTICLE_STATUS).append("=?").
                     append(" AND ").append("b3_solo_tag_article.tag_oId").append(" IN (");