基于php的选课系统 ThinkPHP+MySQL
　选课系统针对不同的用户角色进行管理，设定以下三种角色：学生、教师、管理员，不同角色对应不同权限的操作功能。

　其中学生选课允许同时选择多门课程，但要判断上课时间是否冲突（一二节课与一二三节课也有冲突判断）、限选人数判断等(Course Selection System ThinkPHP+MySQL Based on PHP
Course selection system manages different user roles, setting three roles: students, teachers, administrators, and different roles correspond to the operation functions of different permissions.

Among them, students are allowed to choose multiple courses at the same time, but it is necessary to judge whether the class time is in conflict (one or two classes and one or two or three classes also have conflict judgment), the number of students limited to choose, and so on.)