三层体系结构 我们经常会看到许多应聘者在简历上写着“精通数据库编程”的字样，也经常会在招聘网站上看到软件公司的招聘要求中某一项为“精通数据库编程”。于是这些应聘者去这些软件公司面试，于是我们看到了许多“精通”者落选的现象。 一些程序员在设计数据库应用时，通常会采用数据控件绑定的方法实现。用鼠标拉几个控件，再用鼠标设置几个属性，连键盘都不用动，就完成了一个数据库应用的开发！当然，这的确是一种快速的数据库应用开发方式，但快速并不意味着精通。 对于大型的数据库应用系统，或是拥有众多客户端的应用系统，我们需要另外一种“精通”，这就是几乎每个程序员都听说过的“三层体系结构”。-three-tier architecture we often see many candidates in the curriculum vitae reads "proficient Database Programming" message, often in recruitment website software companies see the recruitment of a request for a "proficient database programming." So these candidates to interview these software companies, so we see a lot of "proficient" who lost the phenomenon. Some programmers in the design database applications, using data normally bind to the control method. Pull a few mouse control, and then attribute several mouse settings, and even keyboards do not have to move, it completed a database application development! Of course, this is really a fast database application development, but does not mean that the rapid proficiency. For large database applications,