XML的局限性　　目前,许多Web网站的内容数据都存放在数据库或数据文件中。对于Web程序开发人员来说,如果要想把有用的信息从数据库中提取出来,传统的方法是在服务器端编写脚本程序(如VBscr ipt、Javascr ipt、CGI、ASP、Perl等等),通过对数据库执行SQL查询得到相关记录,然后把查询结果组织成HTML页面返回给客户端,用户使用浏览器观察最终结果。-Limitations of the current XML, many Web site content data is stored in a database or data file. For Web application developers, if it is to put useful information extracted from the database, the traditional method is to write the server side scr ipt (such as VBscr ipt, Javascr ipt, CGI, ASP, Perl, etc.), through the implementation of the database SQL query to get records, then the query results organized into an HTML page returned to the client, the end user with a browser observed results.