asp.net mvC语言 Linq to SQL Group by and Sum in Select

Question

我需要将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，但我在"a.ArticleName"得到一个错误，说"ArticleName"的定义将丢失。

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

有人和你的想法如何解决这个问题?

谢谢你的帮助!

Answer 1

你得到这个错误，因为分组不返回IEnumerable<OrderedArticle>，但IEnumerable<IGrouping<string, OrderedArticle>>

您需要更改代码以使用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();