Title Description ：
Design an attendance management system , Record the absence of students .
functional requirement ：
(1) Design students （Student）, Record student number , full name , Gender , Is don't , class , Date of birth, etc .
(2) Design courses （Course）, Record course information , For example, course name , Class time （ What day of the week is the class ）, place .
(3) Design attendance class （Attendance）, Record the students' attendance at the course at a specific time .
(4) Enter the student's absence record .
(5) Modify a student's absence record .
(6) Check the absence of a student .
Count... Over a period of time , Name and number of absentees , Sort according to the number of absenteeism .
It's better to have the function of saving data , Ask the great God for help , emergency ！