如何在具有多个表的Linq查询中使用聚合运算符？

Question

I would like to realize below the codes in T-SQL to Linq queries,

select rg.Name, Sum(si.TotalPoint) / Count(si.TotalPoint) from ScoreItem si    
inner join Score s on s.Id = si.ScoreId
inner join ProjectResearchGroup prg on prg.Id = si.ProjectResearchGroupId
inner join RgClone rg on rg.Id = prg.RgCloneId
where rg.Name in (N'26 Gros Kurşun Kalem Stant Skor Kartı'
--,N'A5/A6 Ayaklı Defter Stant Skor Kartı'
--,N'A5/A6 Defter Stant Skor Kartı'
--,N'Adel Metal Stant Skor Kartı')
group by rg.Name
order by Name

Then I have re-wrote them in Linq because I have to use it with EF,

(from si in ScoreItem
       join s in Score on si.ScoreId equals s.Id
       join prg in ProjectResearchGroup on si.ProjectResearchGroupId equals prg.Id
       join rg in RgClone on prg.RgCloneId equals rg.Id 
       group rg by rg.Name into g 
   select new {Name = g.Key, SISScore = g.Sum(rg.TotalPoint) / g.Count(rg.TotalPoint) })

But I have some problems, so if you have any advice, please feel to free and share with me,

Answer 1

Please, read my comments to the question. I think you should correct your query this way:

select new {Name = g.Key, SISScore = g.Average(x=>x.TotalPoint) })

because SUM(Field)/Count(Field) means you want to get average ;)