环境
win7，64位，vs2015
目的
asp.net core 使用Scaffold-DbContext 生成 DbContext 文件
问题
net core生成数据库，使用Scaffold-DbContext报错“‘Scaffold-DbContext’ is not recognized as the name of a cmdlet”
学习的生成数据库信息的文章来自：http://www.cnblogs.com/baobaodong/p/5871357.html
生成的过程
运行的代码是：PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Modles
运行结果如下：
就在网上搜索下，找到一篇：http://www.genshuixue.com/i-cxy/p/12865486
之后我吧代码加上，再次运行 Scaffold-DbContext
提示我powershell版本需要升级，我就从网上下载一个powershell3进行安装，重新启动电脑，但是还是不行，看到如下错误代码
下面看到的错误信息，有看到包名就进行安装下
PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesSystem.AggregateException: One or more errors occurred. ---> Microsoft.EntityFrameworkCore.Design.OperationException: Unable to find design-time provider assembly. Please install the Microsoft.EntityFrameworkCore.SqlServer.Design NuGet package and ensure that the package is referenced by the project. ---> System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.EntityFrameworkCore.SqlServer.Design, Version=1.0.1.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. 系统锟揭诧拷锟斤拷指锟斤拷锟斤拷锟侥硷拷锟斤拷 at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolea n suppressSecurityChecks) at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) at System.Reflection.Assembly.Load(AssemblyName assemblyRef) at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.GetProviderDesignTimeServices(String provider, Boolean throwOnError) --- End of inner exception stack trace --- at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.GetProviderDesignTimeServices(String provider, Boolean throwOnError) at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.Build(String provider) at Microsoft.EntityFrameworkCore.Design.DatabaseOperations.ReverseEngineerAsync(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable
1 schemas, IEnumerable1 tables, Boolean useDataAnnotations, Boolean overw riteFiles, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Design.Internal.OperationExecutor.ReverseEngineerAsync(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable1 schemaFilters, IEnumerable1 tableFilters, Boolean useDataAnnota tions, Boolean overwriteFiles, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Tools.Cli.DbContextScaffoldCommand.<ExecuteAsync>d__1.MoveNext() --- End of inner exception stack trace --- at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions) at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification) at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args) ---> (Inner Exception #0) Microsoft.EntityFrameworkCore.Design.OperationException: Unable to find design-time provider assembly. Please install the Microsoft.EntityFrameworkCore.SqlServer.Design NuGet package and ensure that the package is referenced by th e project. ---> System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.EntityFrameworkCore.SqlServer.Design, Version=1.0.1.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. 系统锟揭诧拷锟斤拷指锟斤拷锟斤拷锟侥硷拷锟斤拷 at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolea n suppressSecurityChecks) at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) at System.Reflection.Assembly.Load(AssemblyName assemblyRef) at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.GetProviderDesignTimeServices(String provider, Boolean throwOnError) --- End of inner exception stack trace --- at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.GetProviderDesignTimeServices(String provider, Boolean throwOnError) at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.Build(String provider) at Microsoft.EntityFrameworkCore.Design.DatabaseOperations.ReverseEngineerAsync(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable1 schemas, IEnumerable1 tables, Boolean useDataAnnotations, Boolean overw riteFiles, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Design.Internal.OperationExecutor.ReverseEngineerAsync(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable1 schemaFilters, IEnumerable1 tableFilters, Boolean useDataAnnota tions, Boolean overwriteFiles, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Tools.Cli.DbContextScaffoldCommand.<ExecuteAsync>d__1.MoveNext()<--- One or more errors occurred. PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesC:\Users\Administrator\Desktop\test7\src\test7\project.json(21,54): warning NU1012: Dependency conflict. Microsoft.EntityFrameworkCore.SqlServer.Design 1.1.0 expected Microsoft.EntityFrameworkCore.SqlServer >= 1.1.0 but received 1.0.1 C:\Users\Administrator\Desktop\test7\src\test7\project.json(24,43): warning NU1012: Dependency conflict. Microsoft.EntityFrameworkCore 1.1.0 expected Microsoft.Extensions.Logging >= 1.1.0 but received 1.0.0 C:\Users\Administrator\Desktop\test7\src\test7\Modles\FirstAppDemoDbContext.cs(14,32): warning CS0114: 'FirstAppDemoDbContext.OnConfiguring(DbContextOptionsBuilder)' hides inherited member 'DbContext.OnConfiguring(DbContextOptionsBuilder)'. To make the cur rent member override that implementation, add the override keyword. Otherwise add the new keyword. C:\Users\Administrator\Desktop\test7\src\test7\Startup.cs(69,30): warning CS0168: The variable 'ex' is declared but never used Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest def inition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args)PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesC:\Users\Administrator\Desktop\test7\src\test7\project.json(21,54): warning NU1012: Dependency conflict. Microsoft.EntityFrameworkCore.SqlServer.Design 1.1.0 expected Microsoft.EntityFrameworkCore.SqlServer >= 1.1.0 but received 1.0.1 C:\Users\Administrator\Desktop\test7\src\test7\Modles\FirstAppDemoDbContext.cs(14,32): warning CS0114: 'FirstAppDemoDbContext.OnConfiguring(DbContextOptionsBuilder)' hides inherited member 'DbContext.OnConfiguring(DbContextOptionsBuilder)'. To make the cur rent member override that implementation, add the override keyword. Otherwise add the new keyword. C:\Users\Administrator\Desktop\test7\src\test7\Startup.cs(69,30): warning CS0168: The variable 'ex' is declared but never used Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest def inition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args)PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesC:\Users\Administrator\Desktop\test7\src\test7\Modles\FirstAppDemoDbContext.cs(14,32): warning CS0114: 'FirstAppDemoDbContext.OnConfiguring(DbContextOptionsBuilder)' hides inherited member 'DbContext.OnConfiguring(DbContextOptionsBuilder)'. To make the current member override that implementation, add the override keyword. Otherwise add the new keyword. C:\Users\Administrator\Desktop\test7\src\test7\Startup.cs(69,30): warning CS0168: The variable 'ex' is declared but never used Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest def inition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args)PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesC:\Users\Administrator\Desktop\test7\src\test7\Modles\FirstAppDemoDbContext.cs(14,32): warning CS0114: 'FirstAppDemoDbContext.OnConfiguring(DbContextOptionsBuilder)' hides inherited member 'DbContext.OnConfiguring(DbContextOptionsBuilder)'. To make the current member override that implementation, add the override keyword. Otherwise add the new keyword. C:\Users\Administrator\Desktop\test7\src\test7\Startup.cs(69,30): warning CS0168: The variable 'ex' is declared but never used Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest def inition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args)PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesC:\Users\Administrator\Desktop\test7\src\test7\Startup.cs(69,30): warning CS0168: The variable 'ex' is declared but never used Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest def inition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args)PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesUnhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args) PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesUnhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at Microsoft.EntityFrameworkCore.Tools.Cli.Program.Main(String[] args) 之前上面看到的错误信息，有看到包名就进行安装下 PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesSystem.InvalidOperationException: The following file(s) already exist in directory C:\Users\Administrator\Desktop\test7\src\test7\Modles: Employee.cs. Use the Force flag to overwrite these files. at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineeringGenerator.CheckOutputFiles(String outputPath, String dbContextClassName, IModel metadataModel, Boolean overwriteFiles) at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineeringGenerator.GenerateAsync(ReverseEngineeringConfiguration configuration, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContextAsync(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable1 schemas, IEnumerable1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.<ScaffoldContextImpl>d__22.MoveNext() at System.Linq.Buffer1..ctor(IEnumerable1 source) at System.Linq.Enumerable.ToArray[TSource](IEnumerable1 source) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass4_01.<Execute>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)The following file(s) already exist in directory C:\Users\Administrator\Desktop\test7\src\test7\Modles: Employee.cs. Use the Force flag to overwrite these files.PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesSystem.InvalidOperationException: The following file(s) already exist in directory C:\Users\Administrator\Desktop\test7\src\test7\Modles: Employee.cs. Use the Force flag to overwrite these files. at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineeringGenerator.CheckOutputFiles(String outputPath, String dbContextClassName, IModel metadataModel, Boolean overwriteFiles) at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineeringGenerator.GenerateAsync(ReverseEngineeringConfiguration configuration, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContextAsync(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable1 schemas, IEnumerable1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.<ScaffoldContextImpl>d__22.MoveNext() at System.Linq.Buffer1..ctor(IEnumerable1 source) at System.Linq.Enumerable.ToArray[TSource](IEnumerable1 source) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass4_0`1.<Execute>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)The following file(s) already exist in directory C:\Users\Administrator\Desktop\test7\src\test7\Modles: Employee.cs. Use the Force flag to overwrite these files.如上说的问题是当前数据库已经存在model里面的类的表了，所以我就改了下数据库里的表的名称，如下就执行成功了
PM> Scaffold-DbContext "Data Source=.;Initial Catalog=test;User ID=sa;Password=sa1234" Microsoft.EntityFrameworkCore.SqlServer -OutputDir ModlesPM>
如果对ASP.NET Core包进行升级的话，版本从1.0至1.1，或其他的包进行了更新之后报错
Scaffold-DbContext : The term 'Scaffold-DbContext' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.At line:1 char:1+ Scaffold-DbContext "Data Source=.;Initial Catalog=testData;User ID=sa;Passw ...+ ~~~~~~~~~~~~~~~~~~ + CategoryInfo : ObjectNotFound: (Scaffold-DbContext:String) [], CommandNotFoundException + FullyQualifiedErrorId : CommandNotFoundException
这样就对“Microsoft.EntityFrameCore”相关的包进行更新下就可以了
如果提示连接数据库语句的问题，看看是不是有安装多个sqlserver版本的数据库，进行区别下就可以了。
如果有找到文档说是需要升级下"Microsoft.EntityFrameworkCore.Tools.DotNet":"1.0.0-preview3-final",安装这个包的时候就会提示此包不支持当前的nuget，这个是在vs2017下应该可以，这个是个人猜测和看文档说的，没有具体实践。
