*　　数据库(文本)

↑

DAL(DATA Access Layer) 数据存取层 --DLL

↑

BLL(BusinessLogicalLayer)交换逻辑层 --DLL

↑

UIL(UserInterfaceLayer)用户接口层 --调用





*项目需求：

Demo （演示文稿）





*调试：F10 执行整个方法

F11 执行单个方法



数据的删出

1.把数据导入内存

2.在内存中删出

3.把信息保存到文件(覆盖原文件)-* Database (text) ↑ DAL (DATA Access Layer) Data Access Layer- DLL ↑ BLL (BusinessLogicalLayer) switching logic layer- DLL ↑ UIL (UserInterfaceLayer) user interface layer- called* Project Requirements: Demo (Presentation)* Debugging: F10 F11 execute the entire method to perform a single method to delete the data as 1. put data into memory 2 out of 3 in memory deleted. the information saved to a file (overwrite the original file)