1．管理信息系统（学生成绩）
两种用户等级：管理员和用户，均用用户名和密码登陆，通过识别不同类型的用户名，进入不同的操作界面。
1) 管理员功能：
i 用户管理：增加、删除用户；
ii 记录录入、修改、删除
iii 查询：单项查询、多项查询、范围查询
iv 分类统计：提供有代表性的统计结果
2) 用户功能：
a) 修改密码
b) 查询本用户信息
c) 修改个人信息
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.000945s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.096024s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001599s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001665s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002404s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003274s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001062s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003782s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015442s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001343s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 420350 [ RunTime:0.122834s ]
