c# - 选择一个不在 LINQ 中的 Group By 子句中的字段

Question

谁能帮我“如何在 LINQ 中选择不在 Group By 子句中的字段”

  var ReportData = 
      from a in context.Table1
      from b in context.Table2
      where a.personelID == b.ID
      && a.DateField.Value.Year == 2011
      group a by new { a.personelID, b.Name, b.Surname} into grouping
      select new
      {
           // grouping.Key.DateField,
          Name= grouping.Key.Name,
          Surname= grouping.Key.Surname,
          PagaBruto =  grouping.Sum(i => i.Bruto)),
      };

我无法选择Table1 中的字段"DateField"，我不想让这个字段出现在Group By，因为我会得到错误的结果。谢谢!

Answer 1

我认为您需要在分组依据之前选择两个表成员，以便您可以从两者中选择数据。我做了一个连接而不是你的 where 子句。

(from a in context.Table1
 join b in context.Table2 on a.PersonalID equals b.ID
 select new { A=a, B=b } into joined
 group joined by new { joined.A.PersonalID, joined.B.Name, joined.B.Surname } into grouped
 select grouped.Select(g => new { 
                                    DateField= g.A.Datefield,
                                    Name = g.B.Name,
                                    Surname = g.B.Surname,
                                    PagaBruto = g.A.Sum(i => i.Bruto)
                                })).SelectMany(g => g);