window平台下实现tail 类似unix下的tail功能，实时跟踪显示文本文件的改变，常用于显示日志文件。-window platform to achieve similar unix tail under the tail function, real-time tracking shows the change text files, which are often used to show the log file.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001266s ]
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:0.100530s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001074s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001924s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001199s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003603s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001036s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003201s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014913s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001338s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 302398 [ RunTime:0.001422s ]
