三层架构\Book_Data.MDF
........\Book_log.LDF
........\MyProject\ProjectDemo\BLL\AssemblyInfo.cs
........\.........\...........\...\bin\Debug\BLL.dll
........\.........\...........\...\...\.....\BLL.pdb
........\.........\...........\...\...\.....\DAL.dll
........\.........\...........\...\...\.....\DAL.pdb
........\.........\...........\...\...\.....\DataModel.dll
........\.........\...........\...\...\.....\DataModel.pdb
........\.........\...........\...\BLL.csproj
........\.........\...........\...\BLL.csproj.user
........\.........\...........\...\Books.cs
........\.........\...........\...\obj\Debug\BLL.dll
........\.........\...........\...\...\.....\BLL.pdb
........\.........\...........\...\...\.....\BLL.projdata
........\.........\...........\DAL\AssemblyInfo.cs
........\.........\...........\...\bin\Debug\DAL.dll
........\.........\...........\...\...\.....\DAL.pdb
........\.........\...........\...\...\.....\DataModel.dll
........\.........\...........\...\...\.....\DataModel.pdb
........\.........\...........\...\BookOperation.cs
........\.........\...........\...\DAL.csproj
........\.........\...........\...\DAL.csproj.user
........\.........\...........\...\obj\Debug\DAL.dll
........\.........\...........\...\...\.....\DAL.pdb
........\.........\...........\...\...\.....\DAL.projdata
........\.........\...........\...\SqlHelper.cs
........\.........\...........\.ataModel\AssemblyInfo.cs
........\.........\...........\.........\bin\Debug\DataModel.dll
........\.........\...........\.........\...\.....\DataModel.pdb
........\.........\...........\.........\Book.cs
........\.........\...........\.........\DataModel.csproj
........\.........\...........\.........\DataModel.csproj.user
........\.........\...........\.........\obj\Debug\DataModel.dll
........\.........\...........\.........\...\.....\DataModel.pdb
........\.........\...........\.........\...\.....\DataModel.projdata
........\.........\...........\ProjectDemo.sln
........\.........\...........\ProjectDemo.suo
........\.........\...........\WinUI\App.ico
........\.........\...........\.....\AssemblyInfo.cs
........\.........\...........\.....\bin\Debug\BLL.dll
........\.........\...........\.....\...\.....\BLL.pdb
........\.........\...........\.....\...\.....\DAL.dll
........\.........\...........\.....\...\.....\DAL.pdb
........\.........\...........\.....\...\.....\DataModel.dll
........\.........\...........\.....\...\.....\DataModel.pdb
........\.........\...........\.....\...\.....\WinUI.exe
........\.........\...........\.....\...\.....\WinUI.pdb
........\.........\...........\.....\Form1.cs
........\.........\...........\.....\Form1.resx
........\.........\...........\.....\obj\Debug\WinUI.exe
........\.........\...........\.....\...\.....\WinUI.Form1.resources
........\.........\...........\.....\...\.....\WinUI.pdb
........\.........\...........\.....\...\.....\WinUI.projdata
........\.........\...........\.....\WinUI.csproj
........\.........\...........\.....\WinUI.csproj.user
........\.........\...........\BLL\obj\Debug\temp
........\.........\...........\...\...\.....\TempPE
........\.........\...........\DAL\obj\Debug\temp
........\.........\...........\...\...\.....\TempPE
........\.........\...........\.ataModel\obj\Debug\temp
........\.........\...........\.........\...\.....\TempPE
........\.........\...........\WinUI\obj\Debug\temp
........\.........\...........\.....\...\.....\TempPE
........\.........\...........\BLL\bin\Debug
........\.........\...........\...\obj\Debug
........\.........\...........\DAL\bin\Debug
........\.........\...........\...\obj\Debug
........\.........\...........\.ataModel\bin\Debug
........\.........\...........\.........\obj\Debug
........\.........\...........\WinUI\bin\Debug
........\.........\...........\.....\obj\Debug
........\.........\...........\BLL\bin
........\.........\...........\...\obj
........\.........\...........\DAL\bin
........\.........\...........\...\obj
........\.........\...........\.ataModel\bin
........\.........\...........\.........\obj
........\.........\...........\Win