Linq查詢計數和GroupBy

Question

誰能告訴我如何在Linq中執行此SQL查詢？

SELECT [id], COUNT(*) FROM [data].[dbo].[MyTable] GROUP BY [id] 

Answer 1

你可以試試這個方法：

var res = ctx.MyTable // Start with your table 
    .GroupBy(r => r.id)/Group by the key of your choice 
    .Select(g => new {Id = g.Key, Count = g.Count()}) // Create an anonymous type w/results 
    .ToList(); // Convert the results to List 

Answer 2

你可以試試這個

var res = from r in MyTable 
      group p by r.id into grouped 
      select new {id = g.key, total = g.Count()}; 

那麼，當你使用它，只是做ToList() 您也可以以後做select new。 我沒有Visual Studio 2010這裏試試，但是 我認爲它會工作