解方程：
用Gauss列主元消元法解线性方程组
-solution equation : Gauss out PCA elimination method for solving linear equations using Gauss out PCA elimination method for solving linear equations
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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:0.088835s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001260s ]
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001220s ]
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SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001050s ]
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SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001335s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 72266 [ RunTime:0.001182s ]
