分组和组合值 DataTable，c#

Question

前：

Name    Class   Ability

Boy1      A1    Sing

Boy2      A1    Sing

Boy3      A2    Sing

Girl1     A2    Sing

Girl2     A2    Dance

后：

Name                Class   Ability

Boy1,Boy2             A1    Sing

Boy3,Girl1,Girl2      A1    Sing,Dance

如何将表格前后分组？我用过：DataTable dt = GetDataTable();//获取数据dt.AsEnumerable()....//不知道怎么继续。请帮我

Answer 1

var result = dt.AsEnumerable()&nbsp; &nbsp; &nbsp;.GroupBy(d => d.Field<string>("Class"))&nbsp; &nbsp; &nbsp;.Select(g => new&nbsp; &nbsp; &nbsp;{&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Name = string.Join(",",&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; g.Select(gn => gn.Field<string>("Name")).Distinct()),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Class = g.Key,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Teacher = string.Join(",",&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; g.Select(gt => gt.Field<string>("Ability")).Distinct())&nbsp; &nbsp; &nbsp;});注意：如果您直接使用 Linq 而不是 DataTable，这会容易得多。

Answer 2

我为样本创建了一个虚拟数据&nbsp; &nbsp; &nbsp; &nbsp; DataTable dtNew, dt = new DataTable();&nbsp; &nbsp; &nbsp; &nbsp; dt.Columns.Add("Id", typeof(string));&nbsp; &nbsp; &nbsp; &nbsp; dt.Columns.Add("Category",typeof(string));&nbsp; &nbsp; &nbsp; &nbsp; dt.Columns.Add("Type",typeof(string));&nbsp; &nbsp; &nbsp; &nbsp; dtNew = dt.Clone();&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323021", "Doors", "900");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323022", "Doors", "900");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323023", "Doors", "1000");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323024", "Doors", "1000");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323025", "Walls", "200");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323026", "Walls", "200");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323027", "Walls", "200");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323028", "Walls", "200");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323026", "Columns", "300x300");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323027", "Columns", "300x300");&nbsp; &nbsp; &nbsp; &nbsp; dt.Rows.Add("323028", "Columns", "500x500");此场景的解决方案&nbsp; &nbsp; &nbsp; &nbsp; //Case 1: Category and Type&nbsp; &nbsp; &nbsp; &nbsp; var caretoryTypeResult = (from b in dt.AsEnumerable()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; group b by new&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Category = b.Field<string>("Category"),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Type = b.Field<string>("Type")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; into grpCategoryType&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; select new&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; grpCategoryType.Key.Category,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; grpCategoryType.Key.Type,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; grpCategoryType&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }).ToList();&nbsp; &nbsp; &nbsp; &nbsp; caretoryTypeResult.ForEach(list => {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var category = list.grpCategoryType.AsEnumerable().Select(m => m.Field<string>("Id")).ToList();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; dtNew.Rows.Add(string.Join(",", category), list.Category, list.Type);&nbsp; &nbsp; &nbsp; &nbsp; });希望这段代码有帮助