Question

I’m trying to convert this rather complex (from my perspective as I don’t deal with SQL) query into LINQ:

SELECT f.description, 
       s.description, 
       file_no,taskid, 
       h.description
       from_userid,
       userid, 
       h.starttime,
       locktime,
       lockby,
       h.status,
       h.endtime
FROM history h 
INNER JOIN flowdefinition f on h.flowid = f.flowid 
INNER JOIN stepdefinition s on h.flowid = s.flowid and h.stepid = s.stepid
WHERE taskid = 'SERVER2012_03_08_09_31_40_367'
AND h.status in ('R','U','C','K')
AND h.flowid not in (999)
order by endtime

And this is what I have so far:

var resultList = from h in context.History_master
                 join f in context.flowdefinition_master on new { h.flowid, h.LocId } equals new { f.flowid, f.LocId } into hf
                 from h in hf.DefaultIfEmpty()
                 join s in context.stepdefinition_master on new { h.stepid, h.LocId } equals new { s.stepid, s.LocId } into hs
                 from s in hs.DefaultIfEmpty()
                 where h.file_no == fileNumber
                 orderby h.endtime
                 select new
                 {

                 };

But this complains that “The range variable ‘h’ conflicts with a previous declaration of ‘h’. I understand that it says it is like a second declaration, but I don’t know how else i would do this in LINQ. Any help with this (complete or partial 🙂 ) would be greatly appreciated!

//EDIT:

If i change the
from h in hf.DefaultIfEmpty() to from h1 in hf.DefaultIfEmpty() as suggested, the h1 does not have the same properties as h. So i can’t do the second join because the tables are not there…

Answer 1

I figured it out. Like other answers said, i had a double declaration, but also the join was not correct. The correct way is like this: (as a Lambda Expression)

 IList<HistoryView> resultList2 = context.History_master.Join(context.flowdefinition_master, h=> new {h.flowid, h.LocId}, f=>new{f.flowid, f.LocId}, (h,f) => new {h,f})
                                                            .Join(context.stepdefinition_master, h=> new {h.h.flowid, h.h.LocId}, s=>new{s.flowid, s.LocId}, (h,s) => new {h,s})
                                                            .Where(x=>x.h.h.file_no == fileNumber)
                                                            .Where(x => (x.h.h.status == "R") || (x.h.h.status == "U") || (x.h.h.status == "C") || (x.h.h.status == "K"))
                                                            .Select(r=> new HistoryView { 
                                                                flowDescription = r.h.f.description,
                                                                stepDescription = r.s.description, 
                                                                fileNumber = r.h.h.file_no,
                                                                taskId = r.h.h.taskid,
                                                                fromUser = r.h.h.from_userid,
                                                                userId = r.h.h.userid,
                                                                startTime = r.h.h.starttime,
                                                                lockTime = r.h.h.locktime,
                                                                lockBy = r.h.h.lockby,
                                                                status = r.h.h.status,
                                                                endTime = r.h.h.endtime
                                                            }).ToList();

Thanks for all the suggestions 🙂