Windows Forms

using System.Data;
using System.Windows.Forms;

class Test {
	DataSet ds;
	
	void SetUpData(){
		ds = new DataSet();
		DataTable dt = new DataTable("lookupTarget");
		DataColumn c = new DataColumn("id", typeof(int)); dt.Columns.Add(c);
		dt.PrimaryKey = new DataColumn[]{ c };
		c = new DataColumn("desc", typeof(string)); dt.Columns.Add(c);
		ds.Tables.Add(dt);
		
		dt = new DataTable("main");
		c = new DataColumn("id", typeof(int)); dt.Columns.Add(c);
		c.AutoIncrement = true;
		dt.PrimaryKey = new DataColumn[]{ c };
		c = new DataColumn("lookup", typeof(int)); dt.Columns.Add(c);
		ds.Tables.Add(dt);
		
		DataRelation dr;
		dr = new DataRelation("testRelation", ds.Tables["main"].Columns["lookup"], ds.Tables["lookupTarget"].Columns["id"], false);
		ds.Relations.Add(dr);
		
	}
	
	void PopulateData(){
		DataRow row;
		
		DataTable lookupTarget = ds.Tables["lookupTarget"];
		DataTable main = ds.Tables["main"];
		
		row = lookupTarget.NewRow();
		row["id"] = 1;
		row["desc"] = "Some stuff";
		lookupTarget.Rows.Add(row);
		
		row = lookupTarget.NewRow();
		row["id"] = 42;
		row["desc"] = "Don't panic";
		lookupTarget.Rows.Add(row);
		
		
		row = main.NewRow();
		row["lookup"] = 1;
		main.Rows.Add(row);

		row = main.NewRow();
		row["lookup"] = 1;
		main.Rows.Add(row);

		row = main.NewRow();
		row["lookup"] = 42;
		main.Rows.Add(row);
	}
	
	Form Form {
		get {
			Form f = new Form();
			DataGrid dgv = new DataGrid();
			dgv.Dock = DockStyle.Fill;
			dgv.DataSource = ds.Tables["main"];
			f.Controls.Add(dgv);
			return f;
		}
	}
	
	static void Main(){
		Test test = new Test();
		test.SetUpData();
		test.PopulateData();
		Application.Run(test.Form);
	}
}