How to implement the following nested SQL as Lambda Statement

Question

I have the following nested SQL Statement and i will to do the same using Lambda statement in C# How do i do it?

SQL:

SELECT board.*, (SELECT COUNT(*) from discussion_topic
                 WHERE TopicBoardID=board.BoardID) as TopicCount
FROM `discussion_board` as board

This is the structure of my 2 tables

Table Name: discussion_board
Fields:
BoardID
BoardName
BoardCreatedBy
BoardCreatedDate

Table Name: discussion_topic
Fields:
TopicID
TopicName
TopicCreatedBy
TopicCreatedDate
TopicBoardID

just 2 simple tables with no Forign Keys,

Thank you!

Answer 1

This will give you a new anonymous type which will have the board record and the count of discussion topics.

var result = dataContext.Board.Select(x => new {x, Count = x.DiscussionTopics.Count()});

You could simply use board.DiscussionTopics.Count(); on each record to get the count. No need to do the above really, if i understand your question correctly

UPDATE

If you have no foreign keys then this might do it

var result = dataContext.Board.Select(x => new {x, Count = dataContext.DiscussionTopics.Count(d => d.TopicBoardId == x.BoardID)});

Answer 2

from b in DataContext.Boards
select new {
    BoardId = b.BoardID,
    BoardName = b.BoardName,
    BoardCreatedBy = b.BoardCreatedBy,
    BoardCreateDate = b.BoardCreateDate,
    TopicCount = Discussions.Count(d => d.TopicBoardId == b.BoardID)
}