INSERT INTO `grade` (grade_id,grade_type,created_at,updated_at) VALUES (1,GD,2019-12-11 07:17:07,2020-03-20 09:01:36);
INSERT INTO `grade` (grade_id,grade_type,created_at,updated_at) VALUES (2,SU,2019-12-13 06:24:16,2020-01-13 08:58:56);
INSERT INTO `grade` (grade_id,grade_type,created_at,updated_at) VALUES (3,AU,2020-01-13 09:04:04,2020-01-28 10:14:07);
INSERT INTO `grade` (grade_id,grade_type,created_at,updated_at) VALUES (4,ST,2020-07-14 06:52:45,2020-07-14 06:52:45);
