Problems using Entity Framework 6 and SQLite

.net c# entity-framework entity-framework-6 sqlite

Question

I'm trying to use Entity Framework with SQLite. I had issues integrating it into my main application, so I started a little test from scratch, exactly following the directions on http://brice-lambson.blogspot.com/2012/10/entity-framework-on-sqlite.html

After all is said and done, I get the following error when running the project:

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

My app.config looks like this:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <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>
  <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>
  <system.data>
    <DbProviderFactories>
      <add name="SQLite Data Provider"
            invariant="System.Data.SQLite"
            description="Data Provider for SQLite"
            type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />
    </DbProviderFactories>
  </system.data>
  <connectionStrings>
    <add name="ChinookContext"
          connectionString=
"Data Source=|DataDirectory|Chinook_Sqlite_AutoIncrementPKs.sqlite"
          providerName="System.Data.SQLite" />
  </connectionStrings>
</configuration>

Then I saw his post about Entity Framework 6. While it wasn't the exact error I was getting, I tried installing his updated provider via NuGet. The error was gone, but replaced with this one:

Could not load file or assembly 'System.Data.SQLite.Linq, Version=2.0.88.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Additionally, my app.config got changed (slightly) to this:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <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>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
      <provider invariantName="System.Data.SQLite" type="System.Data.SQLite.SQLiteProviderServices, System.Data.SQLite.Linq, Version=2.0.88.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139" />
    </providers>
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <add name="SQLite Data Provider" invariant="System.Data.SQLite" description="Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />
      <remove invariant="System.Data.SQLite" />
    </DbProviderFactories>
  </system.data>
  <connectionStrings>
    <add name="ChinookContext" connectionString="Data Source=|DataDirectory|Chinook_Sqlite_AutoIncrementPKs.sqlite" providerName="System.Data.SQLite" />
  </connectionStrings>
</configuration>

I've tried everything I can think of to address these errors, nothing has worked. I've tried using the other SQLite binaries; I've tried manually editing the SQLite project to use the EF version 6; I've changed the architectures, I've added and removed the nuget packages over and over, etc.

I have no idea where to go from here.

1
45
1/25/2016 1:04:01 AM

Accepted Answer

Based on magicandre1981's comment, I began to look more closely at the syntax of the provider node. I found that my assembly was a different version than what was specified in the type attribute, though I had not inserted or touched that particular line. By deleting the strong naming, I got .Net to load the library. For reference, here's the new line:

<provider invariantName="System.Data.SQLite" type="System.Data.SQLite.SQLiteProviderServices, System.Data.SQLite.Linq" />

That put me back on track and I was able to match my results with the ones on the blog.

I feel compelled to note, however, that I have decided that SQLite is not a good fit for the Entity Framework, as too many critical functions are missing. I switched over to SQL Server Compact Edition, which I installed via NuGet. A simple tweak to my Connection String and I was running with the full power of Entity Framework. It took less than a minute, compared to the multi-hour slog that was SQLite. I'd recommend switching databases if possible, System.Data.SQLite just isn't ready for the Entity Framework.

23
11/19/2014 2:47:31 AM

Popular Answer

Just thought I'd share another way to configure EF6 with SQLite without using app.config / web.config. EF6 now supports code based configurations as outlined here on msdn. I used the following code (updated to remove reflection thanks to Sly):

public class SQLiteConfiguration : DbConfiguration
{
    public SQLiteConfiguration()
    {
        SetProviderFactory("System.Data.SQLite", SQLiteFactory.Instance);
        SetProviderFactory("System.Data.SQLite.EF6", SQLiteProviderFactory.Instance);
        SetProviderServices("System.Data.SQLite", (DbProviderServices)SQLiteProviderFactory.Instance.GetService(typeof(DbProviderServices)));
    }
}

I use this so I can inject the correct DbContext and hence DbProvider at runtime and don't need everything configured in the main assembly.

Edit:

As Reyn said you will also need to add an IDbConnectionFactory for SQLite if you wish to have your connection string in your web.config / app.config file. Another approach is to call a different base constructor from your DbContext which passes in a new SQLiteConnection rather than the connection string, as shown in this answer.



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