Question

Is there a relatively straightforward way to get the intersection of two DataTables in .NET?

I can think of the obvious ways (iterating over both tables myself in O(n^2)), but I’d like something a little more elegant if it’s available. I suspect there may be an intelligent way that I’m not seeing. Readability and maintainability are important, of course, so I’m trying to stay away from anything too ‘slick’.

Any good ideas?

EDIT: It looks like Bryan Watts has a pretty great solution for 3.5, but unfortunately I’m in .NET 2.0 (which I should have mentioned.)

Answer 1

With .NET 3.5:

using System.Data;  public static class DataTableExtensions {     public static IEnumerable<DataRow> Intersect(this DataTable table, DataTable other)     {         return table.AsEnumerable().Intersect(other.AsEnumerable());     }      public static IEnumerable<DataRow> Intersect(this DataTable table, DataTable other, IEqualityComparer<DataRow> comparer)     {         return table.AsEnumerable().Intersect(other.AsEnumerable(), comparer);     } }