用三元组表示稀疏矩阵,可以转置 加法，减法，乘法，求逆。- With three Yuan groups expressed the sparse matrix, may
transpose the addition, the subtraction, the multiplication, asks to
go against.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.000960s ]
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:0.077303s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001062s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001415s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000985s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003142s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000916s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003674s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015073s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001015s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 116827 [ RunTime:0.021262s ]
