精确到1us的定时器。使用QueryPerformanceCounter（）函数实现
适用于实时控制环境-accurate to the timer. Use QueryPerformanceCounter () functions applicable to real-time control environment
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.000914s ]
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:0.102083s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001185s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001143s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000968s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003312s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000949s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003623s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.025897s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001052s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 232508 [ RunTime:0.893899s ]
