按层序方式（自上而下，每层自左而右）遍历二叉树,二叉树以二叉链表作为存储-sequence by means (from top to bottom, each of which left from right) traverse binary tree, the binary tree with two forks Chain storage
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.000893s ]
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:0.088572s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.000933s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001121s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001181s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003040s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000799s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003767s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.016353s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001132s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 154631 [ RunTime:0.014497s ]
