base de donnée

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
using System.Text.RegularExpressions;
using System.Runtime.Remoting.Contexts;

namespace projet2
{
    class Program
    {
        static void Main(string[] args)
        {
           

            
            try
            {

                string connectString = "database=dbdotnet;server=SWEET-2D8161F34/SQLEXPRESS;User ID=tester;pwd=tester";
                
                SqlConnection connexion = new SqlConnection(connectString);
                connexion.Open();
                SqlCommand command = new SqlCommand("SELECT * FROM table1", connexion);
                SqlDataReader reader = command.ExecuteReader();
                Console.WriteLine(reader.GetString(1));

             
            }
            catch (Exception ex)
            {
                Console.WriteLine( ex.Message);
            }

            reader.close();
            connexion.close();
        }
    }
}

les erreur:
 Error    1    The name 'reader' does not exist in the current context   
Error    2    The name 'connexion' does not exist in the current context  

bon pouver vous me guider pour resoudre ce problème???

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
using System.Text.RegularExpressions;
using System.Runtime.Remoting.Contexts;

namespace projet2
{
    class Program
    {
        static void Main(string[] args)
        {
          
            string connectString = "database=dbdotnet;server=SWEET-2D8161F34/SQLEXPRESS;User                                           ID=tester;pwd=tester";
            SqlConnection connexion = new SqlConnection(connectString);
            try
            {
                connexion.Open();
                SqlCommand command = new SqlCommand("SELECT * FROM table1", connexion);
                SqlDataReader reader = command.ExecuteReader();
                Console.WriteLine(reader.GetString(1));
                reader.close();
            
            }
            catch (Exception ex)
            {
                Console.WriteLine( ex.Message);
            }
            finally
            {
                connexion.close();
            }
        }
    }
}

bon merci, une erreur persiste déjà :

Error    1    The name 'connexion' does not exist in the current context  

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
using System.Text.RegularExpressions;
using System.Runtime.Remoting.Contexts;

namespace projet2
{
    class Program
    {
        static void Main(string[] args)
        {
          
            string connectString = "database=dbdotnet;server=SWEET-2D8161F34/SQLEXPRESS;User                                           ID=tester;pwd=tester";
            SqlConnection connexion = new SqlConnection(connectString);
            try
            {
                connexion.Open();
                SqlCommand command = new SqlCommand("SELECT * FROM table1", connexion);
                SqlDataReader reader = command.ExecuteReader(); 
                while(reader.Read())
                {
                   Console.WriteLine(reader.GetString(1)); 
                }
                reader.close();
            
            }
            catch (Exception ex)
            {
                Console.WriteLine( ex.Message);
            }
            finally
            {
                connexion.close();
            }
        }
    }
}

Il faut faire avancer le SqlDataReader sur les enregistrements retournés par la requête, ce qui se fait avec reader.Read().

merci krimog pour cette information qui est trèèèèès efficace... mais l'erreur perciste déjà :

Error    1    'System.Data.SqlClient.SqlConnection' does not contain a definition for 'close' and no extension method 'close' accepting a first argument of type 'System.Data.SqlClient.SqlConnection' could be found (are you missing a using directive or an assembly reference?)  

salut tt le monde;
comment faire pour calculer la sommme d'une colonne Sql
svp aider moi