在 Windows 的资源管理器窗口中，我们见过 WinZIP,WinRAR 等软件能在文件或文件夹的默认快捷菜单中添加几个菜单项，它可以使用户无须进入软件内部而直接在视窗中进行压缩/解压操作，十分方便用户操作，这无疑是一个较好的应用模型，它就是我们所说的Shell扩展技术。此源代码将以一个普通的源代码统计程序为例来说明怎样实现Shell扩展技术。
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001311s ]
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:0.091299s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001283s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001875s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001223s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003598s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001054s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003186s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015808s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001435s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 369112 [ RunTime:0.001508s ]
