‫اعمال توابع تجمعی بر روی چند ستون در Entity framework

 SELECT sum([Rating_TotalRating]), sum([Rating_TotalRaters]), sum([Rating_AverageRating]) FROM [BlogPosts]

                context.BlogPost.Select(r =>
                                        new
                                        {
                                            Sum1 = r.Sum(x => x.RatingTotalRating),
                                            Sum2 = r.Sum(x => x.RatingTotalRaters),
                                            Sum3 = r.Sum(x => x.RatingAverageRating)
                                        }).FirstOrDefault();

 var sum1 = context.BlogPost.Sum(x => x.RatingTotalRating);
var sum2 = context.BlogPost.Sum(x => x.RatingTotalRaters);
var sum2 = context.BlogPost.Sum(x => x.RatingAverageRating);

                context.BlogPost
                       .GroupBy(dummyNumber => 0)
                       .Select(r =>
                                        new
                                        {
                                            Sum1 = r.Sum(x => x.RatingTotalRating),
                                            Sum2 = r.Sum(x => x.RatingTotalRaters),
                                            Sum3 = r.Sum(x => x.RatingAverageRating)
                                        }).FirstOrDefault();

SELECT TOP (1) 
                        [Extent1].[K1] AS [K1], 
                        Sum([Extent1].[A1]) AS [A1], 
                        Sum([Extent1].[A2]) AS [A2],
                        Sum([Extent1].[A3]) AS [A3]
                        FROM ( SELECT 
                            0 AS [K1], 
                            [Extent1].[RatingTotalRating] AS [A1], 
                            [Extent1].[RatingTotalRaters] AS [A2],
       [Extent1].[RatingAverageRating] AS [A3]
                            FROM [dbo].[BlogPosts] AS [Extent1]
                        )  AS [Extent1]
                        GROUP BY [K1]