DatabaseAccessLayer

代码说明：

  数据库访问层的通用设计。可根据配置文件的更改适应不同的底层数据库。隔离业务逻辑层。采用C++标准库及ADO方式对数据库进行访问。(The universal design of the database access layer.According to the configuration file changes to adapt to different underlying database. Isolate the business logic layer. C + + standard library and the ADO way to access the database.)