How do I implement a datatable "group by"?

Question

I would like to implement a "Group By" for my datatable. Has any one any suggestions?

update:

c#, .net 2.0

Answer 1

http://stackoverflow.com/questions/499578/c-linq-query-group-by should answer your question, or you could look here: http://msdn.microsoft.com/en-us/vcsharp/aa336754.aspx#simple1

Answer 2

Use LINQ to DataSets and the GroupBy extension methods.

Add assembly System.Data.DataSetExtensions.dll to your project to get access to the AsEnumerable() extension method.

Answer 3

You can use the linq extensions in the System.Data.DataSetExtensions assembly:

DataTable t = //
var groups = t.AsEnumerable()
    .GroupBy(r => r.Field<T>("columnName"))