update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=313;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=244;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=122;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=103;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=147;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=157;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=109;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=470;
update `student_subject_period_average` set `average_ssa`=NULL, `final_average_ssa`=NULL where serial_scy = 2 AND serial_std=340;

update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 313;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 244;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 122;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 103;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 147;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 157;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 109;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 470;
update `discipline` set `subjects_grade_dsc`=NULL,`general_grade_dsc`=NULL where serial_scy = 2 AND serial_std = 340;