我自己开发的一个数据库访问的三层框架，采用了集中常用的模式进行开发。应该能满足最基本的要求，对初学者帮助挺大的。-I have developed a three-tier fr a mework for database access, using a centralized model commonly used for development. Should be able to meet the minimum requirements, for beginners to help Ti