ADO.NET provider with invariant name 'System.Data.SqlClient;' cannot be found (Entity Framework MVC)

Question

I cannot seem to resolve what appears to be a common issue with Entity Framework 6. I have reviewed the many topics related to this issue on SO, and am unable to find a solution that works for my particular case.

I have up until this point been developing using localdb with code first migrations, which worked fine. But now that I am moving this to a actual SQL server instance it throws the following error while attempting migrations:

"The ADO.NET provider with invariant name 'System.Data.SqlClient;' is either not registered in the machine or application config file, or could not be loaded. See the inner exception for details. at System.Data.Common.DbProviderFactories.GetFactory(String providerInvariantName)"

I have attempted the following fixes:

1) Uninstalled and Reinstalled Entity Framework

2) Added the code and used :

public abstract class BaseDomainContext : DbContext
{
 static BaseDomainContext()
 {
 // ROLA - This is a hack to ensure that Entity Framework SQL Provider is copied across to the output folder.
 // As it is installed in the GAC, Copy Local does not work. It is required for probing.
 // Fixed "Provider not loaded" error
 var ensureDLLIsCopied = System.Data.Entity.SqlServer.SqlProviderServices.Instance;
 }
}

as the base class for my DbSet classes.

3) Added everything to a fresh solution and received the same error.

4) Removed the writecontext and tried migrations with just read, still failed.

5) Attempted several rewrites using information from MSDN

6) I have confirmed that EntityFramework.SqlServer.dll is in my bin directory. It is also referenced properly. Plus I have only one project under my solution.

7) Confirmed I am not using the WebConfig under views.

8) Confirmed I have System.Data dll in bin folder.

Image of bin folder

Clean/Rebuilding and deletion of existing migrations folder done after each of the above steps.

I am at a loss to explain why I still am receiving this error.

Web Config

 <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
 <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --></configSections>
 <appSettings>
 <add key="webpages:Version" value="3.0.0.0" />
 <add key="webpages:Enabled" value="false" />
 <add key="ClientValidationEnabled" value="true" />
 <add key="UnobtrusiveJavaScriptEnabled" value="true" />
 </appSettings>
 <connectionStrings>
 <add name="ReadContext" connectionString="Server=Sql2014intsnace;Database=database;User Id=secret; Password=secret;" providerName="System.Data.SqlClient;" />
 <add name="WriteContext" connectionString="Server=Sql2014intsnace;Database=database;User Id=secret; Password=secret;" providerName="System.Data.SqlClient;" />
 </connectionStrings>
 <system.web>
 <compilation debug="true" targetFramework="4.5" />
 <httpRuntime targetFramework="4.5" />
 <authentication mode="Windows" />
 <authorization>
 <deny users="?" />
 </authorization>
 </system.web>
 <system.webServer>
 <handlers>
 <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
 <remove name="OPTIONSVerbHandler" />
 <remove name="TRACEVerbHandler" />
 <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
 </handlers>
 </system.webServer>
 <runtime>
 <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
 <dependentAssembly>
 <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed" />
 <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="0.0.0.0-5.2.2.0" newVersion="5.2.2.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234" />
 </dependentAssembly>
 </assemblyBinding>
 </runtime>
 <entityFramework>
 <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" /> 
 <providers>
 <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
 </providers>
 <contexts> 
 <context type="ProjectName.Models.ReadContext, ProjectName"> 
 <databaseInitializer type="System.Data.Entity.MigrateDatabaseToLatestVersion`2[[ProjectName.Models.ReadContext, ProjectName], [ProjectName.Migrations.Configuration, ProjectName]], EntityFramework" /> 
 </context> 
</contexts>
 </entityFramework>
</configuration>

• jsanalytics: Sounds like you're missing System.Data.dll
• Rasen244: I added more information see image of bin folder. It is copying.
• Rasen244: Yep, that was indeed the problem.

Answer 1

You have this:

<add name="ReadContext" 
 connectionString="Server=Sql2014intsnace;Database=database;User Id=secret; Password=secret;" 
 providerName="System.Data.SqlClient;" /> <-- semi-colon

It should be this:

<add name="ReadContext" 
 connectionString="Server=Sql2014intsnace;Database=database;User Id=secret; Password=secret;" 
 providerName="System.Data.SqlClient" /> <-- no semi-colon

Otherwise, you're telling ADO to find a provider named System.Data.SqlClient; - there isn't one.

Answer 2

I got this error but for me, it was something entirely different. I was able to solve it by looking at only Unable to find the requested .Net Framework Data Provider and finding this answer.

I then had to edit:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config

And:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.config

Searching for DbProviderFactories both configs looked like this:

<system.data>
 <DbProviderFactories>
 <add name="IBM DB2 for i .NET Provider" invariant="IBM.Data.DB2.iSeries" description=".NET Framework Data Provider for IBM i" type="IBM.Data.DB2.iSeries.iDB2Factory, IBM.Data.DB2.iSeries, Version=12.0.0.0, Culture=neutral, PublicKeyToken=9cdb2ebfb1f93a26" />
 </DbProviderFactories>
 <DbProviderFactories />
</system.data>

When I removed the trailing <DbProviderFactories /> everything started working again.

Answer 3

I also had this error and in my case what I had was two projects in my solution, one relying on the other for data access. The project I was using for data access I assumed was the only one that required a reference to EF6, which it did. The project with the calling code did not have any references to Entity Framework and I got the error. I changed the config to referencing Microsoft.Data.Sqlclient from System.Data.SqlClient but that did not help. I don't know why but both projects had to have EF6 installed via NuGet though only one of the projects was invoking Entity Framework. I really don't like it that way, it feels like the solution is too "heavy" but I reverted my config file and referenced EF6 in both of the projects in my solution and that fixed the problem. Just thought I'd share, happy coding!

Answer 4

For me, this issue is caused by damaged EntityFramework. Uninstall EntityFramework as well as Visual Studio and Re-Installing the Visual Studio - The visual studio installation covers the .Net Framework SDK installation kind of resolved this issue.

• Rasen244: No it literally was the fact I included a semi-colon. Though I did try your solution myself before the typo was pointed out to me.