可以使用FileSystemWatcher组件监视文件系统,并对文件系统的改变作出反应。通过使用FileSystemWatcher组件,在特定的文件或目录被创建、修改或删除时,可以快速和便捷地启动业务流程。...
GROUP BYandHAVING By including a GROUP BY clause functions such as SUM and COUNT are applied to groups of items sharing values. When you specify GROUP BY conti...