实现一个普通表达式到后最表达式的转换（只提供了10以内的数的转换）-To achieve a common expression is the best expression to the post-conversion (only 10 less than the number of conversion)
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.002188s ]
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:0.088514s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.002534s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002629s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002457s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.004160s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002067s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003285s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.020822s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.003098s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 212760 [ RunTime:0.001345s ]
