幫助使用簡單的Linq count語句

Question

var q = dc.tblHelpCentreQuestions.Where(c => c.userID == UserID);
q.OrderByDescending(c => c.dateSubmitted);

這工作正常，但我還需要返回從tblHelpCentreReplies返回的記錄計數，其中QuestionID等於tblHelpCentreQuestions.ID 。 在SQL中，這對我來說很容易，有人可以告訴我在LINQ to SQL中是如何完成的嗎？

編輯

我到目前為止：

var q = 
from question in dc.tblHelpCentreQuestions
join replies in dc.tblHelpCentreReplies on question.ID
    equals replies.ticketID
where question.userID == UserID
orderby question.dateSubmitted descending
select new { question, replies.Count() };

但是replies.Count（）拋出：

無效的匿名類型成員聲明符。 必須使用成員分配，簡單名稱或成員訪問來聲明匿名類型成員。

Answer 1

linq查詢如下所示：

var q =
    dc.tblHelpCentreQuestions.
        Where(question => question.userID == UserID).
        OrderByDescending(question => question.dateSubmitted).
        GroupJoin(
            dc.tblHelpCentreReplies,
            question => question.ID,
            replies => replies.ticketID,
            (question, replies) => new {Question = question, RepliesCount = replies.Count()});

如果您有關系映射，請進行更新 ，否則可能會容易一些

var q =
    dc.tblHelpCentreQuestions.
        Where(question => question.userID == UserID).
        OrderByDescending(question => question.dateSubmitted).
        Select(question => new {Question = question, RepliesCount = question.Replies.Count()});

Answer 2

這比您想象的要容易:-)

var q = 
    from question in dc.tblHelpCentreQuestions
    where question.userID == UserID
    orderby question.dateSubmitted desc
    select new { question, question.Replies.Count() };

Answer 3

var q = 
from question in dc.tblHelpCentreQuestions
join replies in dc.tblHelpCentreReplies on question.ID equals replies.ticketID
where question.userID == UserID
orderby question.dateSubmitted descending
select new { Question = question, RepliesCount = replies.Count()};