用反转法实现快速高效的4*4键盘扫描，并通过串口将按键值输出-Inversion method with fast and efficient implementation of the 4* 4 keyboard scanning, and send out the key value through the serial port
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001083s ]
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:0.075523s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.020151s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.017947s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.008700s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.010294s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001545s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.008063s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.026776s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001958s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 139617 [ RunTime:0.014635s ]
