本代码实现普通计算器的计算功能。可以做+，-，*，/运算，是在PB10环境下测试通过的。-code to achieve the common computing functions of the calculator. Operators can do ,-,*,/ is PB10 environment of the test.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001156s ]
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:0.097969s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001093s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001897s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001159s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003571s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001780s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003372s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014952s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001429s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 219677 [ RunTime:0.001220s ]
