多表连接查询

List<R_EquipmentContractInfo> objlist = new List<R_EquipmentContractInfo>();

                //所有的合同
                var contractList = dc_ModelData.Contract_BaseInfor.Where(p => p.BidSectionRowGuid == bidRowGuid).ToList();
                if (contractList == null || contractList.Count() == 0)
                {
                    return objlist;
                }

                //合同所有的物料                
                var allMT = from g in contractList
                            join m in dc_ModelData.MaterialType.Where(p => p.MonomerProject == bidRowGuid && p.Count > 0) on g.RowGuid equals m.ContractRowGuid
                            select m;
                var efiles = (from g in allMT
                              join h in dc_ModelData.EquipmentEFile_Category.Where(p => p.BidSectionRowGuid == bidRowGuid && p.Title == "族文件") on g.RowGuid equals h.MaterialDetailRowGuid into ecGroup
                              from h2 in ecGroup
                              join k in dc_ModelData.EquipmentEFile.Where(p => p.BidSectionRowGuid == bidRowGuid && p.IsMaxVersion == true) on h2.RowGuid equals k.ParentRowGuid into efGroup
                              select new { mt=g,ec=ecGroup,ef=efGroup}).Distinct();

                int mtCount = allMT.Count();
                int ecount = efiles.Count();
                foreach (Contract_BaseInfor ec in contractList)
                {
                    R_EquipmentContractInfo obj = new R_EquipmentContractInfo();
                    obj.rowGuid = ec.RowGuid;
                    obj.name = ec.Name;

                    //总数量
                    List<MaterialType> mmdList = allMT.Where(p=>p.ContractRowGuid == ec.RowGuid).ToList();
                    if (mmdList == null || mmdList.Count == 0)
                    {
                        obj.completeCount = 0;
                        obj.unCompleteCount = 0;
                        objlist.Add(obj);
                        continue;
                    }

                    List<MaterialType> pmmdlist = (from g in mmdList
                                                   join h in efiles on g.RowGuid equals h.mt.RowGuid
                                                   select g).Distinct().ToList();
                    if (pmmdlist == null || pmmdlist.Count == 0)
                    {
                        obj.completeCount = 0;
                    }
                    else
                    {
                        obj.completeCount = pmmdlist.Count;
                    }

                    obj.unCompleteCount = mmdList.Count - obj.completeCount;

                    objlist.Add(obj);

                }


                return objlist;