Database

da.Fill(dataSet1);

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace NorthwindTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string strConnect = @"server = (local)\SQLEXPRESS; integrated security = sspi; database = C:\SQL\NORTHWND.MDF";
            string strQuery1 = @"SELECT * FROM employees";
            string strQuery2 = @"SELECT * FROM orders";
            string strQuery = strQuery1 + strQuery2;


            SqlConnection conn = new SqlConnection(strConnect);
            SqlDataAdapter da = new SqlDataAdapter(strQuery, conn);
            da.TableMappings.Add("Table", "employees");
            da.TableMappings.Add("Table1", "orders");
            da.Fill(dataSet1);
            DataRelation relation = new DataRelation("employeeorders", dataSet1.Tables[0].Columns["employeeid"], dataSet1.Tables[1].Columns["employeeid"]);
            dataSet1.Relations.Add(relation);
            dataGridView1.DataBindings.Add("datasouce", dataSet1, "employees");
        }


    }
}