掌握SQL四条最基本的数据操作语句：Insert，Select，Update和Delete。 　　 练掌握SQL是数据库用户的宝贵财 富。在本文中，我们将引导你掌握四条最基本的数据操作语句—SQL的核心功能—来依次介绍比较操作符、选择断言以及三值逻辑。当你完成这些学习后，显然你已经开始算是精通SQL了。 -master four basic SQL data manipulation statement : Insert, Select, Update and Delete. Train

Vulnerability detection tools are frequently considered the silver-bullet for detecting vulnerabilities in web services. However, research shows that the effectiveness of most of those tools is very low and that using the wrong tool may lead