UPDATE contacts SET grade = NULL, grade_entrance_date = "2016-06-14" WHERE id = "0135055";
UPDATE contacts SET grade = "houka3", grade_entrance_date = "2016-06-10" WHERE id = "0183564";
UPDATE contacts SET grade = "21", grade_entrance_date = "2016-06-14" WHERE id = "0208268";
UPDATE contacts SET grade = "houka2", grade_entrance_date = "2016-06-11" WHERE id = "0217541";