网上选课系统需要实现的功能:

1.　　管理员对学生信息,课程信息和教师信息进行增加、删除、修改、查找等操作，对选课信息进行管理，对成绩信息和用户信息进行修改、查找等操作。

2.　　学生对选课信息进行选课、删除、修改、查找等操作，对学生信息和成绩信息进行查看，对个人的密码信息进行修改等

3.　　教师对学生信息进行增加、删除、修改、查找等操作，对成绩信息进行录入成绩，修改成绩，查询等操作。

-Online elective system needs to achieve the function:

1. The administrator to the student information, curriculum information and teacher information to increase, delete, modify, find and other operations, the selection of information management, performance information and user information to modify, find and other operations.

2. Students on the elective information for elective, delete, modify, find and other operations, the student information and performance information to view, modify the personal password information, etc.

3. Teachers to increase the information of students, delete, modify, find and other operations, the results of information entry results, modify the results, inquiries and other operations.