[Solved] LINQ Error: the type of one of the expression in join is incorrect

Hi Sir,

I have below sql query.

insert into WfrpFarmReportsSubDetail
(MpciCoverageOID,RelatedMpciCoverageOID,AssociatedAipCode,AssociatedAipPolicyNumber,AssociatedAipLocationStateCode,
AssociatedAipLocationCountyCode,AssociatedAipCommodityCode,WrittenAgreement)
select wfrp_mc.OID,rel_mc_new.OID,wfrp.AssociatedAipCode,wfrp.AssociatedAipPolicyNumber,wfrp.AssociatedAipLocationStateCode,
wfrp.AssociatedAipLocationCountyCode,wfrp.AssociatedAipCommodityCode,wfrp.WrittenAgreement
from dbo.MpciPolicy wfrp_mp
inner join dbo.MpciCoverage wfrp_mc on wfrp_mp.OID=wfrp_mc.MpciPolicyOID
inner join dbo.WfrpFarmReportsSubDetail wfrp on wfrp.MpciCoverageOID=wfrp_mc.PreviousOID
inner join dbo.MpciCoverage rel_mc_old on wfrp.RelatedMpciCoverageOID=rel_mc_old.OID
inner join dbo.MpciCoverage rel_mc_new on rel_mc_old.OID=rel_mc_new.PreviousOID
left join dbo.WfrpFarmReportsSubDetail wfrp_ex on wfrp_ex.MpciCoverageOID=wfrp_mc.OID and wfrp_ex.RelatedMpciCoverageOID=rel_mc_new.OID
where wfrp_mp.ReinsuranceYear = @RY and wfrp_mc.CommodityCode = '0076'
and wfrp_mc.CommodityStatus < '7' and wfrp_mc.HasRelatedCoverage = '1' and wfrp.RelatedMpciCoverageOID is not null
and rel_mc_old.CommodityStatus < '7' and rel_mc_new.CommodityStatus < '7'
and wfrp_ex.OID is null

I am trying to write the above query using LINQ.

i am getting the error: the type of one of the expression in join is incorrect. type inference failed for group join.

can anyone suggest me the solution.

What i tried is:

var data = (from mp in mpciPolicyRepository.GetAll()
            join wfrp_mc in mpciCoverageRepository.GetAll() on mp.OID equals wfrp_mc.MpciPolicyOID
            join wfrp in wfrpFarmReportsSubDetailsRepository.GetAll() on wfrp_mc.PreviousOID equals wfrp.MpciCoverageOID
            join rel_mc_old in mpciCoverageRepository.GetAll() on wfrp.RelatedMpciCoverageOID equals rel_mc_old.OID
            join rel_mc_new in mpciCoverageRepository.GetAll() on rel_mc_old.OID equals rel_mc_new.PreviousOID
            join wfrp_ex in wfrpFarmReportsSubDetailsRepository.GetAll()
            on new { a=wfrp_mc.OID, b=rel_mc_new.OID } equals new { a=wfrp_ex.MpciCoverageOID, b=wfrp_ex.RelatedMpciCoverageOID }//
            into wfrpcollection from  subwfrp in  wfrpcollection.DefaultIfEmpty()
            where mp.ReinsuranceYear == reinsuranceYear && wfrp_mc.CommodityCode == "0076" &&
            !MpciCommodityStatusCodeExtensions.CancelledMpciCommodityStatusCodes.Contains(wfrp_mc.CommodityStatus ?? 0)
            && wfrp_mc.HasRelatedCoverage == '1' &&  wfrp.RelatedMpciCoverageOID != null
            && rel_mc_old.CommodityStatus < '7' && rel_mc_new.CommodityStatus < '7'
            && subwfrp == null
            select new WfrpFarmReportsSubDetailViewModel 
            {
                MpciCoverageOID = wfrp_mc.OID,
                RelatedMpciCoverageOID = rel_mc_new.OID,
                AssociatedAipCode = wfrp.AssociatedAipCode,
                AssociatedAipPolicyNumber = wfrp.AssociatedAipPolicyNumber,
                AssociatedAipLocationStateCode = wfrp.AssociatedAipLocationStateCode,
                AssociatedAipLocationCountyCode = wfrp.AssociatedAipLocationCountyCode,
                AssociatedAipCommodityCode = wfrp.AssociatedAipCommodityCode,
                WrittenAgreement = wfrp.WrittenAgreement,
            }).ToList();
//on new { wfrp_ex.MpciCoverageOID, wfrp_ex.RelatedMpciCoverageOID } equals new { wfrp_mc.OID , rel_mc_new.OID }
wfrpFarmReportsSubDetailViewModel.AddRange(data);

Thanks.