不能隐式转换类型'System.Linq.IQueryable'& #

本文关键字：IQueryable AnonymousType#6 Linq System 类型 不能 转换 | 更新日期: 2023-09-27 18:18:31

你好，我有一个这样的linq查询:

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
                              }
                             ),
                   };

问题是，我只想为HK2选择一条记录，并在子查询中分配给Mandays，但下面有一个错误:

不能隐式转换类型"来。可查询'到'decimal'

解决方案是什么?谢谢你

不能隐式转换类型'System.Linq.IQueryable<AnonymousType#6>'& #

不返回匿名类 (new {...})

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

返回您想要的Decimal:

  select g.FirstOrDefault().ManDays;

您应该在末尾添加另一个FirstOrDefault()，并使用简单值而不是匿名类型:

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 
                       };
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