Merge pull request #4 from fujiwara/bulk-insert-unread-announcements

unread announcementsをinsert selectでやる

webapp/go/main.go

@@ -1457,22 +1457,14 @@ func (h *handlers) AddAnnouncement(c echo.Context) error {
 		return c.NoContent(http.StatusInternalServerError)
 	}
 
-	var targets []User
-	query := "SELECT `users`.* FROM `users`" +
-		" JOIN `registrations` ON `users`.`id` = `registrations`.`user_id`" +
+	query := "INSERT INTO `unread_announcements` (`announcement_id`, `user_id`)" +
+		" SELECT ?, `registrations`.`user_id` FROM `registrations`" +
 		" WHERE `registrations`.`course_id` = ?"
-	if err := tx.Select(&targets, query, req.CourseID); err != nil {
+	if _, err := tx.Exec(query, req.ID, req.CourseID); err != nil {
 		c.Logger().Error(err)
 		return c.NoContent(http.StatusInternalServerError)
 	}
 
-	for _, user := range targets {
-		if _, err := tx.Exec("INSERT INTO `unread_announcements` (`announcement_id`, `user_id`) VALUES (?, ?)", req.ID, user.ID); err != nil {
-			c.Logger().Error(err)
-			return c.NoContent(http.StatusInternalServerError)
-		}
-	}
-
 	if err := tx.Commit(); err != nil {
 		c.Logger().Error(err)
 		return c.NoContent(http.StatusInternalServerError)