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internal/database/articles.go

@@ -133,3 +133,43 @@ func ArticleByID(store *Store, ID int, slug string) (article model.DisplayArticl
 
 	return result, nil
 }
+
+func PreviousAndNextArticleUrlByID(store *Store, ID int) (nextUrl string, previousUrl string, err error) {
+
+	nextResult, previousResult := "#", "#"
+	query, err := store.Prepare(`
+     select id,title, content, slug, original_url, source_id, created_at from articles where id = $1;
+		 `)
+	if err != nil {
+		return nextResult, previousResult, err
+	}
+	defer query.Close()
+
+	row := query.QueryRow(ID - 1)
+	if err != nil {
+		return nextResult, previousResult, err
+	}
+
+	r := model.DisplayArticle{}
+	content := ""
+	err = row.Scan(&r.ID, &r.Title, &content, &r.Slug, &r.OriginalUrl, &r.SourceId, &r.CreatedAt)
+	if err != nil {
+		return nextResult, previousResult, err
+	}
+
+	previousResult = fmt.Sprintf("/%d/%s", r.ID, r.Slug)
+
+	row = query.QueryRow(ID + 1)
+	if err != nil {
+		return nextResult, previousResult, err
+	}
+
+	content = ""
+	err = row.Scan(&r.ID, &r.Title, &content, &r.Slug, &r.OriginalUrl, &r.SourceId, &r.CreatedAt)
+	if err != nil {
+		return nextResult, previousResult, err
+	}
+	nextResult = fmt.Sprintf("/%d/%s", r.ID, r.Slug)
+
+	return nextResult, previousResult, nil
+}