如何使用聯接從Linq查詢的第二個表中拉出一列

Question

我有以下運行良好的linq查詢，但是我想從context.Emps中拉出一列（CompanyId）以及context.BillingProfiles的結果。 我將如何修改下面的選擇（選擇教授）以包括所述列？

var query = (from prof in context.BillingProfiles
             join emp in context.Emps on prof.ID equals emp.ID
             join grp in context.BillingGroups on prof.GroupID equals grp.GroupID
             where (prof.EndDate == null) && (grp.System == "sysGrp") && (prof.ID == id)
             select prof).Distinct()
            .Select(x => new OpId()
            {
                id = x.ID,                                        
                GroupId = x.GroupID,
                OpId = x.OpID,
                StartDate = x.StartDate,
                EndDate = x.EndDate,
                AddedOn = x.AddedOn,
                AddedBy = x.AddedBy,
                RemovedOn = x.RemovedOn,
                RemovedBy = x.RemovedBy,
                Prodid = x.ProdID,
            });

謝謝

Answer 1

投影一個也包含這些對象的匿名對象：

var query = from prof in context.BillingProfiles
            join emp in context.Emps on prof.ID equals emp.ID
            join grp in context.BillingGroups on prof.GroupID equals grp.GroupID
            where prof.EndDate == null && prof.ID == id && grp.System == "sysGrp"
            select new { prof, emp.CompanyId, grp };