找不到实体框架ADO.NET Sql.Data.Client提供程序

Question

我有一个问题类似于 No Entity Framework提供者为ADO.NET提供程序找到的具有不变名称'System.Data.SqlClient'的问题,该错误有以下消息:

"具有不变名称'System.Data.SqlClient'的ADO.NET提供程序未在机器或应用程序配置文件中注册,或者无法加载.有关详细信息,请参阅内部异常."

正如相关问题的答案所示,我已经通过软件包管理器控制台重新安装了实体框架(EF6),但错误仍然存​​在.我还检查了我的项目中引用了EntityFramework.SqlServer.dll.这是存储在App.config中的连接字符串:

<add name="DesignModel"    ConnectionString="metadata=res://*/DesignModel.csdl|res://*/DesignModel.ssdl|res://*/DesignModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=C071E;initial catalog=CTD2;integrated security=True;multipleactiveresultsets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />     

我有另一个项目,我使用EntityFramework创建完全相同的实体和上下文,它工作正常,这使得这更令人费解.

尝试执行此行时会显示错误:

DesignModel designContext = new DesignModel();
designContext.MoPerfIDs.Load();

其中DesignModel是继承DbContext的类的名称.

这是完整的App.config:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
       <section name="ppe.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
    </sectionGroup>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
      <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>

  <connectionStrings>
    <add name="DesignModel" connectionString="metadata=res://*/DesignModel.csdl|res://*/DesignModel.ssdl|res://*/Design    Model.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=MONNMC071E;initial catalog=CTD2;integrated security=True;multipleactiveresultsets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
  </connectionStrings>

<entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
        <parameters>
            <parameter value="System.Data.SqlClient" />
        </parameters>
    </defaultConnectionFactory>
    <providers>
        <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
</entityFramework>
</configuration>

任何帮助将不胜感激.提前致谢.

Answer 1

哇……这很特别……无论如何。您需要为System.Data.SqlClientSQL 连接类型注册实体框架提供程序。

您想将以下内容添加到您的app.config/web.config

<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="System.Data.SqlClient" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
</configuration>