Question

I have an MVC app using Linq to Entities and I’m having a hard time figuring out how to get this part of a query written. This is an excerpt from a SQL Stored Procedure that works. I know I can use the procedure but I’m trying to get a better understanding of LINQ. The goal is to get the last Routing for a requisition and the ReqRoutingID is an identity filed so the last entry in the table is always the one I want.

SELECT
    h.ReqID,
    rr.RoutingSectionID
FROM LOG_ReqHeader h
JOIN dbo.Log_ReqRoutings rr
    ON  rr.ReqRoutingID = (
        SELECT TOP 1 r.ReqRoutingID
        FROM Log_ReqRoutings r1
        WHERE r1.ReqID = h.ReqID 
        ORDER BY r1.ReqRoutingID desc)

Answer 1

var query = from h in db.LOG_ReqHeader
            from rr in db.Log_RequRoutings
            where rr.ReqRoutingID == (from r1 in db.Log_RequRoutings
                                      where r1.Req == h.ReqID
                                      orderby r1.ReqRoutingID descending
                                      select r1).FirstOrDefault().ReqRoutingID
            select new { h.ReqID, rr.RoutingSectionID };