1..n
Student
-ID:String-name:String-password:String-realName:String-gender:int-nativePlace:String-IDNumber:String-telphone:String-email:String
+querySingleCourseScore()+queryAllCourseScore();
1
Course
-ID:String-course_Name:String-grade:String-type:String
+insert()+update()+delete()...
