No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'.

问题

We are using EntityFramework 6 with Code First. We have a console app that has no reference to EntityFramework but reads the connection string from its App.config. It calls the DatabaseInitializationUtilities assembly passing the connection string as a parameter.

DatabaseInitializationUtilities has the reference to EF6 (EntityFramework and EntityFramework.SqlServer). Its App.config is this:

<?xml version="1.0" encoding="utf-8"?>
  <configuration>
     <configSections>
        <!-- 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>
     <system.serviceModel>
         <bindings>
            <basicHttpBinding>
                <binding name="BasicHttpBinding_IAuthentication" />
            </basicHttpBinding>
         </bindings>
         <client>
            <endpoint address="http://localhost/SecurityServices/Authentication.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IAuthentication" contract="SecurityService.IAuthentication" name="BasicHttpBinding_IAuthentication" />
         </client>
      </system.serviceModel>
      <entityFramework>
         <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
            <parameters>
               <parameter value="v11.0" />
            </parameters>
         </defaultConnectionFactory>
         <providers>
            <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
         </providers>
      </entityFramework>
   </configuration>

When execution reaches a line where DatabaseInitializationUtilities attempts to run a script

context.Database.ExecuteSqlCommand(script.ScriptText)

the error is thrown:

No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'. Make sure the provider is registered in the 'entityFramework' section of the application config file. See http://go.microsoft.com/fwlink/?LinkId=260882 for more information.

I believe the remedy is exactly what I have in my config file, so I don't understand the problem.

NOTE: Resharper is bluelining the node and reporting "The element 'EntityFramework' has an invalid child element 'providers'. However, the section was injected by NuGet when I installed EF6.

Any ideas?

回答1:

You need to create a reference, so it will be copied in the debug folder. So later it can accessed in runtime.

Don't to copy any files, just create this reference:

private volatile Type _dependency;

public MyClass()
{
    _dependency = typeof(System.Data.Entity.SqlServer.SqlProviderServices);
}

回答2:

do you have the assembly EntityFramework.SqlServer.dll in your application path? I had the same Problem and after copying the dll into the application path every Thing worked fine.

回答3:

Finally found the answer in this blog:

http://robsneuron.blogspot.com/2013/11/entity-framework-upgrade-to-6.html

回答4:

I had this problem too. Everything worked locally when I ran my .net mvc app but when I published it I got this error. The problem was that I had to reference the EntityFrameworl.SqlServer also in my web project alhough I had seperate project for Data. What is strange is that this error was only thrown when app was published. This is some serious bug probably from Microsoft. I used EF 6.1.1.

回答5:

This is because EntityFramework.SqlServer.dllis not copied into your project. Add that dll and it will hopefully work.You can find that from the project where you added datamodel.

回答6:

For me it turned out that my provider reference in the web.config file was incorrect. I believe that the nuget package might not properly include the provider.

I replaced my provider with this and it worked:

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

回答7:

I also had a similar problem

My problem was solved by doing the following:

回答8:

The best way to get ride of such a kind of problem is to include the reference EntityFramework.SqlServer.dll into your project the press F4 (op the properties) change the property to Copy to Local =True so each and every time when publish the app it will be copied to the published folder.

回答9:

I tend to add EntityFramework to the web project as well as the assembly that actually references it.

回答10:

Add "EntityFramework.SqlServer.dll" into your project bin folder will resolved your issue.

来源：https://stackoverflow.com/questions/21175713/no-entity-framework-provider-found-for-the-ado-net-provider-with-invariant-name