Question

我只想在Linq中执行此SQL。但是如何？

Select Id, sum(Count) 
from dbo.BThread 
group by Id 
order by sum(Count) desc

我尝试了这个并且失败了：结果只给出了一行。我期待比这更多的行。我需要总结许多ID。

var List = (from tbBThread in context.BThread.Take(10)
                group tbBThread by tbBThread.Id into bTmp
                orderby bTmp.Sum(x => x.Count)
                select new BViewModel
                {
                    Id = bTmp.Key,
                    Id = bTmp.First().Id,
                    Count = bTmp.Sum(x => x.Count)
                }).ToList();

Answer 1

Take(10)应该在查询的末尾。

var List = (from tbBThread in context.BThread
            group tbBThread by tbBThread.Id into bTmp
            orderby bTmp.Sum(x => x.Count)
            select new BViewModel
            {
                Id = bTmp.Key,
                Count = bTmp.Sum(x => x.Count)
            }).Take(10).ToList();

否则，您只会查看context.BThread的前10个元素，这些元素似乎具有相同的Id，因此会进入同一组。

并且（正如Slai已在评论中所述）删除第二个Id = bTmp.First().Id,。

Linq集团由总和订购

1 个答案: