.net core Scaffold DbContext（EF核心工具）抛出'；实例失败'；例外

上下文

目前，我正在创建一个用C#编写的.NET内核的提取、转换和加载（ETL）应用程序。ETL应用程序的目标是通过EntityFrameworkCore2.1.0和更高版本的2.1.1访问的数据库。使用数据库优先的方法，因为模式是固定的。Microsoft提供了以下方法来解决这种情况。该指南指出，可以使用Package Manager控制台中的CLI命令

Scaffold DbContext

生成DbContext和相应的实体模型

在本项目的前面，我已经成功地使用了这个CLI命令。但是，模型的命名与表名和列名并不直接对应。此CLI工具的较新版本提供了一个选项

-UseDatabaseNames

，因此我选择重新运行此命令以生成一些更新的模型。此外，我计划在将来更经常地重新生成DbContext

问题

不幸的是，现在运行

Scaffold DbContext

命令会返回以下错误：

实例失败。

。详细选项可以让我们更深入地了解出了什么问题，但我不清楚到底出了什么问题以及如何解决

命令

详细输出

例外情况

System.invalidoOperationException:实例失败。
在System.Data.SqlClient.TdsParser.Connect（ServerInfo ServerInfo、sqlinternalconnectionds connHandler、Boolean ignoresnopentimeout、Int64 timerExpire、Boolean encrypt、Boolean trustServerCert、Boolean integratedSecurity、Boolean with failover）
位于System.Data.SqlClient.SqlInternalConnectionDS.AttemptOneLogin（ServerInfo ServerInfo、String newPassword、SecureString newSecurePassword、Boolean IgnoresInOpenTimeout、TimeoutTimer timeout、Boolean withFailover）
位于System.Data.SqlClient.SqlInternalConnectionDS.LoginOfAliver（ServerInfo服务器信息、字符串newPassword、SecureString newSecurePassword、布尔重定向EducserInstance、SqlConnectionString连接选项、SqlCredential凭证、超时超时）
位于System.Data.SqlClient.SqlInternalConnectionDS.OpenLoginList（超时计时器超时、SqlConnectionString连接选项、SqlCredential凭证、字符串新密码、SecureString NewSecureUserPassword、布尔重定向EduceInstance）
位于System.Data.SqlClient.SqlInternalConnectionDS..ctor（DbConnectionPoolIdentity标识、SqlConnectionString连接选项、SqlCredential凭据、对象提供程序信息、字符串新密码、SecureString newSecurePassword、布尔重定向声明、SqlConnectionString用户连接选项、SessionData重新连接SessionData、布尔applyTransientFaultHandling）
位于System.Data.SqlClient.SqlConnectionFactory.CreateConnection（DbConnectionOptions、DbConnectionPoolKey、Object poolGroupProviderInfo、DbConnectionPool、DBConnectionOwningConnection、DbConnectionOptions用户选项）
位于System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection（DbConnectionPool池、DbConnectionOwningObject、DbConnectionOptions选项、DbConnectionPoolKey池键、DbConnectionOptions用户选项）
位于System.Data.ProviderBase.DbConnectionPool.CreateObject（DbConnection-owningObject、DbConnectionOptions-userOptions、DbConnectionInternal-oldConnection）
位于System.Data.ProviderBase.DbConnectionPool.UserCreateRequest（DbConnection owningObject、DbConnectionOptions userOptions、DbConnectionInternal oldConnection）
位于System.Data.ProviderBase.DbConnectionPool.TryGetConnection（DbConnection owningObject、UInt32 waitForMultipleObjectsTimeout、Boolean allowCreate、Boolean OnlyOnEckConnection、DbConnectionOptions userOptions、DbConnectionInternal和connection）
位于System.Data.ProviderBase.DbConnectionPool.TryGetConnection（DbConnection owningObject、TaskCompletionSource`1重试、DbConnectionOptions用户选项、DbConnectionInternal和connection）
位于System.Data.ProviderBase.DbConnectionFactory.TryGetConnection（DbConnection owningConnection、TaskCompletionSource`1重试、DbConnectionOptions用户选项、DbConnectionInternal oldConnection、DbConnectionInternal&connection）
位于System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal（DbConnection outerConnection、DbConnectionFactory connectionFactory、TaskCompletionSource`1重试，DbConnectionOptions用户选项）
位于System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection（DbConnection outerConnection、DbConnectionFactory connectionFactory、TaskCompletionSource`1重试、DbConnectionOptions用户选项）
位于System.Data.SqlClient.SqlConnection.TryOpen（TaskCompletionSource`1重试）
在System.Data.SqlClient.SqlConnection.Open（）处
在Microsoft.EntityFrameworkCore.SqlServer.Scaffolding.Internal.SqlServerDatabaseModelFactory.Create（数据库连接、IEnumerable`1表、IEnumerable`1模式）
位于Microsoft.EntityFrameworkCore.SqlServer.Scaffolding.Internal.SqlServerDatabaseModelFactory.Create（字符串连接字符串、IEnumerable`1表、IEnumerable`1模式）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseeEngineerCafFolder.ScaffoldModel（字符串连接字符串、IEnumerable`1表、IEnumerable`1模式、字符串命名空间、字符串语言、字符串contextDir、字符串contextName、ModelReverseeEngineerOptions模型选项、ModelCodeGenerationOptions代码选项）
位于Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext（字符串提供程序、字符串连接字符串、字符串outputDir、字符串outputContextDir、字符串dbContextClassName、IEnumerable`1模式、IEnumerable`1表、布尔useDataAnnotations、布尔重写文件、布尔useDatabaseNames）
位于Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl（字符串提供程序、字符串连接字符串、字符串输出目录、字符串输出数据库上下文目录
Scaffold-DbContext "[ConnectionString]" Microsoft.EntityFrameworkCore.SqlServer -UseDatabaseNames -OutputDir Models -v -force

Using project '[ProjectName]'.
Using startup project '[ProjectName]'.
Build started...
Build succeeded.
C:\Program Files\dotnet\dotnet.exe exec --depsfile C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\bin\Debug\netcoreapp2.1\[ProjectName].Service.deps.json --additionalprobingpath C:\Users\[MyComputerUsername]\.nuget\packages --additionalprobingpath "C:\Program Files\dotnet\sdk\NuGetFallbackFolder" --runtimeconfig C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\bin\Debug\netcoreapp2.1\[ProjectName].Service.runtimeconfig.json C:\Users\[MyComputerUsername]\.nuget\packages\microsoft.entityframeworkcore.tools\2.1.1\tools\netcoreapp2.0\any\ef.dll dbcontext scaffold Server=[ConnectionString] Microsoft.EntityFrameworkCore.SqlServer --json --output-dir Models --use-database-names --force --verbose --no-color --prefix-output --assembly C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\bin\Debug\netcoreapp2.1\[ProjectName].Service.dll --startup-assembly C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\bin\Debug\netcoreapp2.1\[ProjectName].Service.dll --project-dir C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\ --language C# --working-dir C:\Repos\[Client]\[ProjectName]\[ProjectName] --root-namespace [ProjectName].Service
Using assembly '[ProjectName]'.
Using startup assembly '[ProjectName]'.
Using application base 'C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\bin\Debug\netcoreapp2.1'.
Using working directory 'C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service'.
Using root namespace '[ProjectName]'.
Using project directory 'C:\Repos\[Client]\[ProjectName]\[ProjectName]\[ProjectName].Service\'.
The EF Core tools version '2.1.1-rtm-30846' is older than that of the runtime '2.1.2-rtm-30932'. Update the tools for the latest features and bug fixes.
Finding design-time services for provider 'Microsoft.EntityFrameworkCore.SqlServer'...
Using design-time services from provider 'Microsoft.EntityFrameworkCore.SqlServer'.
Finding design-time services referenced by assembly '[ProjectName]'.
No referenced design-time services were found.
Finding IDesignTimeServices implementations in assembly '[ProjectName]'...
No design-time services were found.

System.InvalidOperationException: Instance failure.
   at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover)
   at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
   at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
   at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
   at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, Boolean applyTransientFaultHandling)
   at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at Microsoft.EntityFrameworkCore.SqlServer.Scaffolding.Internal.SqlServerDatabaseModelFactory.Create(DbConnection connection, IEnumerable`1 tables, IEnumerable`1 schemas)
   at Microsoft.EntityFrameworkCore.SqlServer.Scaffolding.Internal.SqlServerDatabaseModelFactory.Create(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas, String namespace, String language, String contextDir, String contextName, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions)
   at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable`1 schemas, IEnumerable`1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable`1 schemaFilters, IEnumerable`1 tableFilters, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
Instance failure.