Как в c# правильно делать mssql update?

public void DBTableUpdate(int id, int col1, int col2, int col3)
{
	string connectionString = GetDBConnectionString();

	using (SqlConnection connection = new SqlConnection(connectionString))
	{
		SqlCommand command = new SqlCommand();
		command.Connection = connection;

		command.Parameters.AddWithValue("@id", id);
		command.Parameters.AddWithValue("@col1", col1);
		command.Parameters.AddWithValue("@col1", col2);
		command.Parameters.AddWithValue("@col1", col3);
		
		command.CommandType = System.Data.CommandType.Text;
		string commandText = "UPDATE dbo.tablename SET col1=@col1,col2=@col2,col3=@col3 WHERE id=@id;";
		
		try
		{
			Console.WriteLine(String.Format("Executing SQL: {0}", command.CommandText));

			connection.Open();
			Int32 rowsAffected = command.ExecuteNonQuery();

			Console.WriteLine(String.Format("RowsAffected: {0}", rowsAffected));
		}
		catch (SqlException ex)
		{
			Console.WriteLine(String.Format("SqlException: [{0}] {1}", ex.ErrorCode, ex.Message));
		}
		catch (InvalidOperationException ex)
		{
			Console.WriteLine(String.Format("InvalidOperationException: {1}", ex.Message));
		}
	}
}

private string GetDBConnectionString(string Server, string Database, string Username, string Password)
{
	return string.Format("Data Source={0};Initial Catalog={1};User ID={2};Password={3}", Server, Database, Username, Password);
}