Layer-3 development framework

1: database data access layer
2: business logic layer
3: Module Business Entity Layer
4: web layer
The data access layer is responsible for extending data type support. The key point is the uniqueness of the data connection object. the business logic layer processes data according to the specific business logic. The key point is to reflect the data to the database based on the business operation data. In the business logic layer, some methods such as string operations can be encapsulated, file operations such as XML operations, of course, you can also take this part CodeSeparate layers. The web layer mainly initializes business entities and server data detection. In the three-layer framework, the moduel layer is responsible for transmitting data between each layer.