在oracle中sequence就是所谓的序列号，每次取的时候它会自动增加，一般用在需
要按序列号排序的地方。
-oracle in which sequence is the so-called sequence, each time for it would automatically increase general use by the need to sort the sequence of places.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001019s ]
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:0.066223s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001052s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001249s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000964s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003182s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000875s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003925s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014665s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001185s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 223100 [ RunTime:0.014801s ]
