c# - 如何将多行组合成单个文本？

Question

我想像这样将电话号码分组到同一部分:

section | phone
   1    | 1001
   1    | 1002
   2    | 1201
   2    | 1202

然后像这样将它们分组:

section | phone
   1    | 1001, 1002
   2    | 1201, 1202

但我不知道摸索它们的语法。

我做的这段代码

var entgr = (from fx in MainOnline.MA_TelUsers
             where fx.TE_SectionID != null
             group fx by fx.TE_SectionID into id
             from ids in id.DefaultIfEmpty()
             select new 
             { 
                  Section = ids.TE_SectionID,
                  TelPhone = ids.TE_Phone                                         
             });

我如何对其进行分组并使用它来加入其他表？

Answer 1

var entgr = (from fx in ph
                         group fx by fx.SectionId.ToString() into id
                         select new
                         {
                             Section = id.Key,
                             TelPhone = string.Join(", ",id.Select(s => s.PhoneNumber.ToString()))
                         });