Csharp/C Sharp/Database ADO.net/SQL Events

How to use the InfoMessage event

using System;
using System.Data;
using System.Data.SqlClient;
class InfoMessage
{
  public static void InfoMessageHandler(object mySender, SqlInfoMessageEventArgs myEvent)
  {
    Console.WriteLine("The following message was produced:\n" + myEvent.Errors[0]);
  }
  public static void Main(){
    SqlConnection mySqlConnection = new SqlConnection("server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI;");
    mySqlConnection.InfoMessage += new SqlInfoMessageEventHandler(InfoMessageHandler);
    mySqlConnection.Open();
    SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
    mySqlCommand.rumandText = "PRINT "This is the message from the PRINT statement"";
  
    mySqlCommand.ExecuteNonQuery();
    mySqlCommand.rumandText = "RAISERROR("This is the message from the RAISERROR statement", 10, 1)";
  
    mySqlCommand.ExecuteNonQuery();
    mySqlConnection.Close();
  }
}

How to use the StateChange event

using System;
using System.Data;
using System.Data.SqlClient;
class StateChange
{
  public static void StateChangeHandler(object mySender, StateChangeEventArgs myEvent)
  {
    Console.WriteLine("mySqlConnection State has changed from "+myEvent.OriginalState + "to "+myEvent.CurrentState);
  }
  public static void Main(){
    SqlConnection mySqlConnection =new SqlConnection("server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI;");
    mySqlConnection.StateChange +=new StateChangeEventHandler(StateChangeHandler);
    Console.WriteLine("Calling mySqlConnection.Open()");
    mySqlConnection.Open();
    Console.WriteLine("Calling mySqlConnection.Close()");
    mySqlConnection.Close();
  }
}

On row updating and updated event

using System;
using System.Data;
using System.Data.SqlClient;
   class SqlDemo {
      static void Main(){
         string connString = "server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
         SqlConnection cn = new SqlConnection(connString);
         try
         {
            cn.Open();
            SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Employee", cn);
     
            SqlCommandBuilder cb = new SqlCommandBuilder(da);
            DataSet ds = new DataSet();
            da.Fill(ds, 0, 1, "Employee");
            da.RowUpdating += new SqlRowUpdatingEventHandler(OnRowUpdating);
            da.RowUpdated += new SqlRowUpdatedEventHandler(OnRowUpdated);
            DataTable dt = ds.Tables["Employee"];
            dt.Rows[0][1] = "T";
            da.Update(ds, "Employee");
            da.RowUpdating -= new SqlRowUpdatingEventHandler(OnRowUpdating);
            da.RowUpdated -= new SqlRowUpdatedEventHandler(OnRowUpdated);
 
         } catch (SqlException ex) {
            Console.WriteLine(ex.Message);
         }
         finally
         {
            cn.Close();
         }
      }

      static void OnRowUpdating(object sender, SqlRowUpdatingEventArgs e) 
      {
         Console.WriteLine("OnRowUpdating event");
         if (e.Status != UpdateStatus.Continue) 
            Console.WriteLine("RowStatus = " + e.Status.ToString());
      } 
      static void OnRowUpdated(object sender, SqlRowUpdatedEventArgs e) 
      {
         Console.WriteLine("OnRowUpdating event");
         if (e.Status != UpdateStatus.Continue) 
            Console.WriteLine("RowStatus = " + e.Status.ToString());
      }
  }

Register two SqlConnection change events

using System;
using System.Data;
using System.Data.SqlClient;
   class SqlDemo {
      static void Main(){
         string connString = "server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
         SqlConnection cn = new SqlConnection(connString);
         cn.StateChange += new StateChangeEventHandler(CnStateChange);
         cn.StateChange += new StateChangeEventHandler(CnStateChange2);
      
         SqlCommand cmd = new SqlCommand();
         cmd.rumandText = "SELECT LastName, FirstName FROM Employee";
         cmd.Connection = cn;
         try
         {
            cn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            while(dr.Read())
            {
               Console.WriteLine(dr.GetString(0) + "-" + dr.GetString(1));    
            }
         }
         catch(SqlException ex)
         {
            Console.WriteLine (ex.Message);
         }
         finally
         {
            cn.Close();
         }   
      }
      static void CnStateChange2(object sender, StateChangeEventArgs ev)
      {
         Console.WriteLine("------------------------------");
         Console.WriteLine("Entering Second Statechange EventHandler");
         Console.WriteLine("Sender = " + sender.ToString());  
         Console.WriteLine("Original State = " + ev.OriginalState.ToString());
         Console.WriteLine("Current State = " + ev.CurrentState.ToString());    
         Console.WriteLine("Exiting Second StateChange EventHandler");
         Console.WriteLine("------------------------------");
      }
      
      static void CnStateChange(object sender, StateChangeEventArgs ev)
      {
         Console.WriteLine("------------------------------");
         Console.WriteLine("Entering StateChange EventHandler");
         Console.WriteLine("Sender = "+ sender.ToString());
         Console.WriteLine("Original State = "+ ev.OriginalState.ToString());
         Console.WriteLine("Current State = "+ ev.CurrentState.ToString()); 
         Console.WriteLine("Exiting StateChange EventHandler");
         Console.WriteLine("------------------------------");
      }
   }