无法隐式转换类型“System.Linq.IQueryable <AnonymousType＃6>”到“小数”

Question

喂，我有一个LINQ查询是这样的：

var data = from d in db.DailyBonus 
        where d.Date>= startDate1 && d.Date<=endDate1 
        group d by new { Em = d.Employee.Id } into g 
        select new BasisViewModel 
        { 
         EmployeeId = g.Key.Em, 
         EmployeeNumber = g.FirstOrDefault().Employee.EmployeeNumber, 
         FullName = g.FirstOrDefault().Employee.FullName, 
         HK1 = (decimal)g.FirstOrDefault().ManDays, 
         Basis1 = (decimal)g.FirstOrDefault().BonusBase, 
         HK2 = (
           (from d in db.DailyBonus 
           where d.Date>= startDate2 && d.Date<=endDate2 
           group d by new { Em = d.Employee.Id } into g2 
           select new 
           { 
           Mandays = g.FirstOrDefault().ManDays <-- this is decimal type 
           } 
          ), 
        }; 

的问题是，我只是想选择一个记录为HK2和子查询分配到的人力，时间，但有波纹管的错误：

无法隐式转换类型 “System.Linq.IQueryable”到“小数”

解决方案是什么？谢谢

Answer 1

不是返回匿名类（new {...}）

select new 
    { 
     Mandays = g.FirstOrDefault().ManDays <-- this is decimal type 
    } 

回报Decimal你想要的：

select g.FirstOrDefault().ManDays; 

Answer 2

你应该再添FirstOrDefault()到底和使用简单的值，而不是匿名类型：

var data = from d in db.DailyBonus 
         where d.Date>= startDate1 && d.Date<=endDate1 
         group d by new { Em = d.Employee.Id } into g 
         select new BasisViewModel 
         { 
          EmployeeId = g.Key.Em, 
          EmployeeNumber = g.FirstOrDefault().Employee.EmployeeNumber, 
          FullName = g.FirstOrDefault().Employee.FullName, 
          HK1 = (decimal)g.FirstOrDefault().ManDays, 
          Basis1 = (decimal)g.FirstOrDefault().BonusBase, 
          HK2 = (
            (from d in db.DailyBonus 
            where d.Date>= startDate2 && d.Date<=endDate2 
            group d by new { Em = d.Employee.Id } into g2 
            select g.FirstOrDefault().ManDays <-- this is simple value now 

           ).FirstOrDefault(),<--this is another first or default 
         };