c# - LINQ 子查询、分组依据和计数

Question

我刚刚开始使用 LINQ 编写查询，这就是我对它不是很熟悉的原因。我的查询在 SQL 中运行良好，但我想在其 LINQ 表达式中替换它。

SELECT DISTINCT Libelle
FROM Question, Connaissance
WHERE Question.ID_Q = Connaissance.ID_Question and ID_Q = (SELECT ID_Question
FROM Connaissance
GROUP BY ID_Question
HAVING COUNT(ID_Reponse) >= ALL(SELECT COUNT(ID_Reponse)
FROM Connaissance
GROUP BY ID_Question))

(Libelle是Question表中Question的名称)

我试过类似的东西:

var question = from q in dc.Question
               join a in dc.Connaissance on q.ID_Q equals a.ID_Question
               group q by a.ID_Question into grp
               where grp.Count() >= ???

问题是我不知道如何转换这部分:>= ALL(SELECT COUNT(ID_Reponse)。我试图在 Internet 上搜索类似的东西，但没有找到任何东西。

如果有人能帮助我，我将不胜感激......

Answer 1

这样可以吗？

var question =
    from q in dc.Question
    join a in dc.Connaissance on q.ID_Q equals a.ID_Question
    group q by a.ID_Question into grp
    where grp.Count() >= dc.Connaissance.Select(y => y.ID_response).Distinct().Count()