Merge pull request #722 from isucon/fix/webapp-rm-grade-tx

成績取得のトランザクションを消す

webapp/golang/main.go

@@ -559,20 +559,13 @@ func (h *handlers) GetGrades(c echo.Context) error {
 		return c.NoContent(http.StatusInternalServerError)
 	}
 
-	tx, err := h.DB.Beginx()
-	if err != nil {
-		c.Logger().Error(err)
-		return c.NoContent(http.StatusInternalServerError)
-	}
-	defer tx.Rollback()
-
 	// 履修している科目一覧取得
 	var registeredCourses []Course
 	query := "SELECT `courses`.*" +
 		" FROM `registrations`" +
 		" JOIN `courses` ON `registrations`.`course_id` = `courses`.`id`" +
 		" WHERE `user_id` = ?"
-	if err := tx.Select(&registeredCourses, query, userID); err != nil {
+	if err := h.DB.Select(&registeredCourses, query, userID); err != nil {
 		c.Logger().Error(err)
 		return c.NoContent(http.StatusInternalServerError)
 	}
@@ -588,7 +581,7 @@ func (h *handlers) GetGrades(c echo.Context) error {
 			" FROM `classes`" +
 			" WHERE `course_id` = ?" +
 			" ORDER BY `part` DESC"
-		if err := tx.Select(&classes, query, course.ID); err != nil {
+		if err := h.DB.Select(&classes, query, course.ID); err != nil {
 			c.Logger().Error(err)
 			return c.NoContent(http.StatusInternalServerError)
 		}
@@ -598,13 +591,13 @@ func (h *handlers) GetGrades(c echo.Context) error {
 		var myTotalScore int
 		for _, class := range classes {
 			var submissionsCount int
-			if err := tx.Get(&submissionsCount, "SELECT COUNT(*) FROM `submissions` WHERE `class_id` = ?", class.ID); err != nil {
+			if err := h.DB.Get(&submissionsCount, "SELECT COUNT(*) FROM `submissions` WHERE `class_id` = ?", class.ID); err != nil {
 				c.Logger().Error(err)
 				return c.NoContent(http.StatusInternalServerError)
 			}
 
 			var myScore sql.NullInt64
-			if err := tx.Get(&myScore, "SELECT `submissions`.`score` FROM `submissions` WHERE `user_id` = ? AND `class_id` = ?", userID, class.ID); err != nil && err != sql.ErrNoRows {
+			if err := h.DB.Get(&myScore, "SELECT `submissions`.`score` FROM `submissions` WHERE `user_id` = ? AND `class_id` = ?", userID, class.ID); err != nil && err != sql.ErrNoRows {
 				c.Logger().Error(err)
 				return c.NoContent(http.StatusInternalServerError)
 			} else if err == sql.ErrNoRows || !myScore.Valid {
@@ -638,7 +631,7 @@ func (h *handlers) GetGrades(c echo.Context) error {
 			" LEFT JOIN `submissions` ON `users`.`id` = `submissions`.`user_id` AND `submissions`.`class_id` = `classes`.`id`" +
 			" WHERE `courses`.`id` = ?" +
 			" GROUP BY `users`.`id`"
-		if err := tx.Select(&totals, query, course.ID); err != nil {
+		if err := h.DB.Select(&totals, query, course.ID); err != nil {
 			c.Logger().Error(err)
 			return c.NoContent(http.StatusInternalServerError)
 		}
@@ -682,12 +675,7 @@ func (h *handlers) GetGrades(c echo.Context) error {
 		" LEFT JOIN `submissions` ON `users`.`id` = `submissions`.`user_id` AND `submissions`.`class_id` = `classes`.`id`" +
 		" WHERE `users`.`type` = ?" +
 		" GROUP BY `users`.`id`"
-	if err := tx.Select(&gpas, query, StatusClosed, StatusClosed, Student); err != nil {
-		c.Logger().Error(err)
-		return c.NoContent(http.StatusInternalServerError)
-	}
-
-	if err := tx.Commit(); err != nil {
+	if err := h.DB.Select(&gpas, query, StatusClosed, StatusClosed, Student); err != nil {
 		c.Logger().Error(err)
 		return c.NoContent(http.StatusInternalServerError)
 	}