ASP.NET MVC 4プロジェクトでPostgreSQLとEntity Framework 6を使いたいです。私はEntity Framework 6.0.2 + Npgsql 2.0.14.3を取得しましたが、エラーが発生します。これをどうやって解決するのですか?Entity Framework 6 with Npgsql
エラー:
An exception of type 'System.InvalidOperationException' occurred in mscorlib.dll but was not handled in user code
Additional information: The 'Instance' member of the Entity Framework provider type 'Npgsql.NpgsqlServices, Npgsql, Version=2.0.14.3, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' did not return an object that inherits from 'System.Data.Entity.Core.Common.DbProviderServices'. Entity Framework providers must inherit from this class and the 'Instance' member must return the singleton instance of the provider. This may be because the provider does not support Entity Framework 6 or later; see http://go.microsoft.com/fwlink/?LinkId=260882 for more information.
のWeb.config
<system.data>
<DbProviderFactories>
<add name="Npgsql Data Provider"
invariant="Npgsql"
description="Data Provider for PostgreSQL"
type="Npgsql.NpgsqlFactory, Npgsql" />
</DbProviderFactories>
</system.data>
<connectionStrings>
<add name="DatabaseContext" connectionString="Server=localhost;port=5432;Database=main;User Id=postgres;Password=password;" providerName="Npgsql" />
</connectionStrings>
<entityFramework>
<providers>
<provider invariantName="Npgsql" type="Npgsql.NpgsqlServices, Npgsql" />
</providers>
</entityFramework>
を書くことができることを見出しました。それを見てください:http://stackoverflow.com/a/21839153/246097 –