主从式DataSet

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

namespace DataSet1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private BindingSource deptBS = new BindingSource();
        private BindingSource empBS = new BindingSource();

        //主从式DataSet
        private void Form1_Load(object sender, EventArgs e)
        {
            string connStr = ConfigurationManager.ConnectionStrings["sqlconn"].ConnectionString;
            SqlConnection conn = new SqlConnection(connStr);
            conn.Open();

            DataSet ds = new DataSet("mydb");

            string deptSql = "select * from dept";
            string empSql = "select * from emp";

            SqlDataAdapter deptAdapter = new SqlDataAdapter(deptSql, conn);
            SqlDataAdapter empAdapter = new SqlDataAdapter(empSql, conn);
            deptAdapter.Fill(ds, "dept");
            empAdapter.Fill(ds, "emp");

            DataColumn deptCol = ds.Tables["dept"].Columns["deptno"];
            DataColumn empCol = ds.Tables["emp"].Columns["deptno"];

            DataRelation relation = new DataRelation("r", deptCol, empCol);
            ds.Relations.Add(relation);

            deptBS.DataSource = ds.Tables["dept"];
            empBS.DataSource = deptBS;
            empBS.DataMember = "r";

            dataGridView1.DataSource = deptBS;
            dataGridView2.DataSource = empBS;

        }
    }
}