Question

This is the error which arises when I tried to debug an application under Visual C# 2010

I write that code to retrieve some rows from a database table, I already attached the two well known databases Pubs and Northwind to the db explorer, but the error remains

class Author
{
    SqlConnection _pubConnection;
    string _connString;

    public Author()
    {
        _connString = "Data Source=./INSTANCE2;Initial Catalog=pubs;Integrated Security=True";
        _pubConnection = new SqlConnection();
        _pubConnection.ConnectionString = _connString;
    }

    public int CountAuthors()
    {
        try
        {
            SqlCommand pubCommand = new SqlCommand();
            pubCommand.Connection = _pubConnection;
            pubCommand.CommandText = "Select Count(au_id) from authors";
            _pubConnection.Open();
            return (int)pubCommand.ExecuteScalar();
        }
        catch (SqlException ex)
        {
            throw ex;
        }
        finally
        {
            if (_pubConnection != null)
            {
                _pubConnection.Close();
            }
        }
    }
}

static void Main(string[] args)
{
   try
   {
      Author author = new Author();
      Console.WriteLine(author.CountAuthors());
      Console.ReadLine();
   }
   catch (Exception ex)
   {
      Console.WriteLine(ex.Message);
      Console.ReadLine();
   }
}

Answer 1

the Connection string isn’t ok , i correct it and it works fine