在线考试系统一共包含两种权限的用户角色，分别是学生和老师。老师可以录入试题，对已录入的试题进行查看、修改和删除，还可以根据试题题目查询 试题。老师还可以查询指定学生成绩，查询一个班级中所有学生的成绩。学生可以随机获取一套试题、对试卷进行答题、查看考试成绩以及查看自己试卷的正确答案和解析。(Online examination system contains two kinds of user roles, namely, students and teachers. The teacher can input test questions, check, modify and delete the items that have been entered, and can also ask questions based on questions. The teacher can also inquire the assigned student's achievement, inquire all student's achievement in a class. Students can get a set of questions randomly, answer questions, check exam results and check the correct answers and analysis of their test papers.)