帮助使用简单的Linq count语句

Question

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

这工作正常，但我还需要返回从tblHelpCentreReplies返回的记录计数，其中QuestionID等于tblHelpCentreQuestions.ID 。 在SQL中，这对我来说很容易，有人可以告诉我在LINQ to SQL中是如何完成的吗？

编辑

我到目前为止：

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（）抛出：

无效的匿名类型成员声明符。 必须使用成员分配，简单名称或成员访问来声明匿名类型成员。

Answer 1

linq查询如下所示：

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()});

如果您有关系映射，请进行更新 ，否则可能会容易一些

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

Answer 2

这比您想象的要容易:-)

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()};