一本书上提供的一个线性表的类，感觉不错，我再VC上调试通过了，希望可以有帮助
-First book to provide a linear form of the class, I feel good, I would like to debug through the VC, and hope to have help
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.002818s ]
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:0.138132s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.002632s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.003231s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002985s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.004016s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002196s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003444s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.019384s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.003113s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 190605 [ RunTime:0.001235s ]
