Linq to SQL Group by和Sum in Select

Question

我需要将该SQL查询转换为Linq:

SELECT
    SUM([ArticleAmount]) as amount
    ,[ArticleName]
FROM [DB].[dbo].[OrderedArticle]

group by articlename

order by amount desc

我尝试了下面的代码,但是我在"a.ArticleName"上收到一个错误,指出"ArticleName"的定义会丢失.

var sells = orderedArt
            .GroupBy(a => a.ArticleName)
            .Select(a => new {Amount = a.Sum(b => b.ArticleAmount),Name=a.ArticleName})
            .OrderByDescending(a=>a.Amount)
            .ToList();

有你的人,并想知道如何解决这个问题？

谢谢你的帮助!

Answer 1

您收到此错误,因为分组没有返回IEnumerable<OrderedArticle>,但IEnumerable<IGrouping<string, OrderedArticle>>

您需要更改要使用的代码a.Key:

var sells = orderedArt
    .GroupBy(a => a.ArticleName)
    .Select(a => new { Amount = a.Sum(b => b.ArticleAmount), Name = a.Key})
    .OrderByDescending(a => a.Amount)
    .ToList();