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

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connetionString = null;
            SqlConnection connection ;
            SqlCommand command ;
            SqlDataAdapter adapter = new SqlDataAdapter();
            DataSet ds = new DataSet();
            string firstSql = null;
            string secondSql = null;
            connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password";
            firstSql = "Your First SQL Statement Here";
            secondSql = "Your Second SQL Statement Here";
            connection = new SqlConnection(connetionString);
            try
            {
                connection.Open();
                command = new SqlCommand(firstSql, connection);
                adapter.SelectCommand = command;
                adapter.Fill(ds, "Table1");

                adapter.SelectCommand.CommandText = secondSql;
                adapter.Fill(ds, "Table2");

                adapter.Dispose();
                command.Dispose();
                connection.Close();
                //creating data relations 
                DataRelation relation ;
                DataColumn table1Column ;
                DataColumn table2Column ;
                //retrieve column 
                table1Column = ds.Tables["Table1"].Columns[0];
                table2Column = ds.Tables["table2"].Columns[0];
                //relating tables 
                relation = new DataRelation("relation", table1Column, table2Column);
                //assign relation to dataset 
                ds.Relations.Add(relation);

                MessageBox.Show ("Data relation completed");
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }
        }
    }
}