PHP+MySQL高校学生考勤管理系统，实现学生的考勤情况，包括记录学生缺课以及作业提交情况，查询、修改、删除学生缺课记录以及统计某时间段内旷课情况(PHP+MySQL university student attendance management system, realize the attendance of students, including records of students absent and job submission, query, modify, delete s