FastCount for SQL Server and EntityFramework

FastCount.cs

public static class QueryExtensions
{
    public static long FastCount<TEntity>(this DbContext context) where TEntity : class
    {
        var name = context.GetTableName<TEntity>();
        var sql =
            $@"SELECT SUM (row_count)
            FROM sys.dm_db_partition_stats
            WHERE object_id=OBJECT_ID('{name}')
            AND (index_id=0 or index_id=1);";

        var results = context.Database.SqlQuery<long>(sql);
        return results.First();
    }

    // table name query courtesy of http://stackoverflow.com/a/27216884/54342
    public static string GetTableName<T>(this DbContext context) where T : class
    {
        var objectContext = ((IObjectContextAdapter)context).ObjectContext;
        return objectContext.GetTableName(typeof(T));
    }

    public static string GetTableName(this DbContext context, Type t)
    {
        var objectContext = ((IObjectContextAdapter)context).ObjectContext;
        return objectContext.GetTableName(t);
    }


    private static readonly ConcurrentDictionary<Type, string> TableNames = new ConcurrentDictionary<Type, string>();
    public static string GetTableName(this ObjectContext context, Type t)
    {
        return TableNames.GetOrAdd(t, type =>
        {
            var storageMetadata = context.MetadataWorkspace.GetItems<EntityContainerMapping>(DataSpace.CSSpace);
            var entityName = t.Name;

            foreach (var ecm in storageMetadata)
            {
                EntitySet entitySet;
                if (ecm.StoreEntityContainer.TryGetEntitySetByName(entityName, true, out entitySet))
                {
                    return entitySet.Schema + "." + entitySet.Table;//TODO: brackets
                }
            }

            return "";
        });

    }
}