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:0.001532s ]
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:0.091448s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001128s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001164s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001088s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003354s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000930s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.005293s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.025935s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001674s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 154631 [ RunTime:0.017090s ]
