表达式求值，通过栈，计算加减乘除，可以做小数，整数负数等运算-Expression is evaluated, through the stack, calculate addition and subtraction multiplication and division, can do decimals, negative integers such as computing
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001284s ]
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:0.087427s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001259s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001914s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001248s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003570s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001060s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003652s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014292s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001297s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 172490 [ RunTime:0.001236s ]
