控制流语句if-else-end，并且用学生成绩举例，创建Hilbert矩阵，n阶魔方矩阵，编写一个M函数文件-Control-flow statements if-else-end, and with student achievement, for example, create a Hilbert matrix, n-order magic square matrix, the preparation of an M function file
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.000986s ]
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:0.102151s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001206s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001640s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001114s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003555s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001132s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003998s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.017854s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001017s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 3925 [ RunTime:0.016046s ]
