using System;
using System.Data;
using System.Data.SqlClient;

///

///

Demonstrates how to work with SqlConnection objects
///
class SqlConnectionDemo
{
static void Main()
{
// 1. Instantiate the connection
SqlConnection conn = new SqlConnection(
"Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI");

SqlDataReader rdr = null;

try
{
// 2. Open the connection
conn.Open();

// 3. Pass the connection to a command object
SqlCommand cmd = new SqlCommand("select * from Customers", conn);

//
// 4. Use the connection
//

// get query results
rdr = cmd.ExecuteReader();

// print the CustomerID of each record
while (rdr.Read())
{
Console.WriteLine(rdr[0]);
}
}
finally
{
// close the reader
if (rdr != null)
{
rdr.Close();
}

// 5. Close the connection
if (conn != null)
{
conn.Close();
}
}
}
}