如何解决：无法加载或组装 Npgsql 或其依赖项之一

Question

我正在尝试使用 C# 创建一个 API，但由于我必须启用迁移，所以出现以下错误：

The ADO.NET provider with invariant name 'Npgsql' is either not registered in the machine or application config file, or could not be loaded. See the inner exception for details.

我正在使用 EntityFramework 6.2.0 和 EntityFramework.Npgsql 3.2.1.1，在将以下代码片段插入 Web.config 之后：

<system.data>
    <DbProviderFactories>
      <remove invariant="Npgsql" />
      <add name="Npgsql Data Provider" invariant="Npgsql" description=".Net Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7" support="FF" />
    </DbProviderFactories>
  </system.data>

现在我遇到了这个问题：

Checking if the context targets an existing database...
System.IO.FileLoadException: Could not load file or assembly 'Npgsql, Version=4.1.1.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
File name: 'Npgsql, Version=4.1.1.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' ---> System.IO.FileLoadException: Could not load file or assembly 'Npgsql, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
File name: 'Npgsql, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7'

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

   at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type)
   at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName)
   at System.RuntimeType.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark)
   at System.Type.GetType(String typeName)
   at System.Data.Common.DbProviderFactories.GetFactory(DataRow providerRow)
   at System.Data.Common.DbProviderFactories.GetFactory(String providerInvariantName)
   at System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup)
   at System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.<>c__DisplayClass1.<GetService>b__0(Tuple`2 k)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.GetService(Type type, Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.<>c__DisplayClass3.<GetService>b__0(IDbDependencyResolver r)
   at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
   at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.GetService(Type type, Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.RootDependencyResolver.GetService(Type type, Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.<>c__DisplayClass3.<GetService>b__0(IDbDependencyResolver r)
   at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
   at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.GetService(Type type, Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.CompositeResolver`2.GetService(Type type, Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.DbDependencyResolverExtensions.GetService[T](IDbDependencyResolver resolver, Object key)
   at System.Data.Entity.Internal.LazyInternalConnection.CreateConnectionFromProviderName(String providerInvariantName)
   at System.Data.Entity.Internal.LazyInternalConnection.InitializeFromConnectionStringSetting(ConnectionStringSettings appConfigConnection)
   at System.Data.Entity.Internal.LazyInternalConnection.TryInitializeFromAppConfig(String name, AppConfig config)
   at System.Data.Entity.Internal.LazyInternalConnection.Initialize()
   at System.Data.Entity.Internal.LazyInternalConnection.get_Connection()
   at System.Data.Entity.Internal.LazyInternalContext.get_Connection()
   at System.Data.Entity.Infrastructure.DbContextInfo..ctor(Type contextType, DbProviderInfo modelProviderInfo, AppConfig config, DbConnectionInfo connectionInfo, Func`1 resolver)
   at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext, DatabaseExistenceState existenceState, Boolean calledByCreateDatabase)
   at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
   at System.Data.Entity.Migrations.Design.MigrationScaffolder..ctor(DbMigrationsConfiguration migrationsConfiguration)
   at System.Data.Entity.Migrations.Design.ToolingFacade.ScaffoldRunner.RunCore()
   at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()


Could not load file or assembly 'Npgsql, Version=4.1.1.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Warning     Found conflicts between different versions of "Npgsql" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.

我正在使用 EntityFramework 6.2.0 和 EntityFramework.Npgsql 3.2.1.1。

Answer 1

安装 npgsql 版本 4.1.1 安装包 Npgsql -版本 4.1.1

Answer 2

下载https://github.com/npgsql/npgsql/releases/download/v4.1.8/Npgsql.msi

然后安装。

查看更多信息

https://github.com/npgsql/npgsql/tree/v4.1.8

https://www.npgsql.org/doc/installation.html#windows-msi-installer

如何解决：无法加载或组装 Npgsql 或其依赖项之一

How to solve : could not load or assembly Npgsql or one of its dependencies

c#

postgresql

entity-framework-6