linq - 使用组获取 linq 错误

Question

添加 linq 分组时出现以下错误。

错误 5“System.Linq.IGrouping”不包含“Description”的定义，并且找不到接受“System.Linq.IGrouping”类型的第一个参数的扩展方法“Description”（您是否缺少 using 指令或装配参考？）

using (var db = new DataContext())
{
     var query = from emp in db.Employees
                               .Where( e=> e.IsDeleted == false && e.DivisionId == divisionId)
                 from rev in db.Reviews
                               .Where( r=> r.EmployeeID == emp.EmployeeId && r.IsDeleted == false && r.ReviewPeriodId == reviewPeriodId)
                               .DefaultIfEmpty()
                 from obj in db.Objectives
                               .Where( o=> o.ReviewId == rev.ReviewId && o.IsDeleted == false)
                               .DefaultIfEmpty()
                 from objps in db.ObjectiveProgressStatusLanguages
                                .Where( s=> s.ObjectiveProgressStatusId == obj.ObjectiveProgressStatusId && s.LanguageId == langueageId)
                                .DefaultIfEmpty()
                 group objps by new {objps.Description, objps.StatusId into opsgroup

                 select new
                 { 
                     Status = opsgroup.Description, 
                     StatusId = opsgroup.StatusId,
                     Count = opsgroup.Count()  
                 };
    return query.CopyToDataTable();

Answer 1

这些字段应该是 Key 的一部分。尝试将其更改为：

  select new {
        Status = opsgroup.Key.Description,
        StatusId = opsgroup.Key.StatusId,
        Count = opsgroup.Count()
  }