How do I use Entity Framework 6 with MySQL in ASP.

问题:

I have an existing site that uses ASP.NET MVC 4, Entity Framework 6 and MySQL. I'm trying to upgrade it to ASP.NET 5, but want to continue using Entity Framework 6 as Entity Framework is missing some features and does not yet support MySQL. How do I use EF6 in ASP.NET 5?

回答1:

Since Web.config is no longer used with ASP.NET 5, you need to use code-based configuration to configure it instead. To do so, create a new class that inherits from DbConfiguration:

public class MyDbConfiguration : DbConfiguration
{
    public MyDbConfiguration()
    {
        // Register ADO.NET provider
        var dataSet = (DataSet)ConfigurationManager.GetSection("system.data");
        dataSet.Tables[0].Rows.Add(
            "MySQL Data Provider",
            ".Net Framework Data Provider for MySQL",
            "MySql.Data.MySqlClient",
            typeof(MySqlClientFactory).AssemblyQualifiedName
        );

        // Register Entity Framework provider
        SetProviderServices("MySql.Data.MySqlClient", new MySqlProviderServices());
        SetDefaultConnectionFactory(new MySqlConnectionFactory());
    }
}

The first part of the configuration is a hack to register the ADO.NET provider at runtime, by dynamically adding a new configuration entry to the system.data section. This is very hacky, but does appear to work correctly.

Add the connection string to config.json rather than Web.config:

{
  "Data": {
    "DefaultConnection": {
      "ConnectionString": "Server=localhost; Database=test; Uid=test; Pwd=password;"
    }
  }
}

Modify the DbContext to use the correct configuration and connection string:

[DbConfigurationType(typeof(MyDbConfiguration))]
public class MyContext : DbContext
{
    public MyContext(IConfiguration config)
      : base(config["Data:DefaultConnection:ConnectionString"])
      {
      }
      // ...
}

Register MyContext in the dependency injection container in Startup.cs:

public void ConfigureServices(IServiceCollection services)
{
    // ...
    services.AddScoped<MyContext>();
}

Then you can just use constructor injection to get MyContext into your controllers.

More details in my blog post at http://dan.cx/2015/08/entity-framework-6-mysql-aspnet, and a sample project at https://github.com/Daniel15/EFExample