Execute complicated SQL query

   


using System;
using System.Data;
using System.Data.OleDb;

public class ExtractInfo {    
 public static void Main () { 
   String connect = "Provider=Microsoft.JET.OLEDB.4.0;data source=.Employee.mdb";
   OleDbConnection con = new OleDbConnection(connect);
   con.Open();  
   Console.WriteLine("Made the connection to the Sales database");
   OleDbCommand cmd = con.CreateCommand();
   
   cmd.CommandText = "SELECT DISTINCT CustomerName "
            + "FROM Customer, Item, Orders, OrderItem "
            + "WHERE Customer.CustomerID = Orders.CustomerID "
            + "AND Orders.OrderNumber = OrderItem.OrderNumber "
            + "AND OrderItem.ItemNumber = Item.ItemNumber "
            + "AND Description = 'computer'";
   OleDbDataReader reader = cmd.ExecuteReader();
   while(reader.Read())
     Console.WriteLine(reader.GetString(0));
   reader.Close();



   con.Close();
 }
}