title: MySql.Data.MySqlClient.MySqlException : 'There is already an open DataReader associated with this Connection which must be closed first.'
body: <pre><code>MySqlCommand Sql1 = new MySqlCommand("SELECT * FROM animal WHERE idAnimal ='" + label1.Text + "'", Connection);
  
  MySqlDataReader dr1;
  dr1 = Sql1.ExecuteReader();
  
  while (dr1.Read())
  {
      String idAnimal = dr1["idAnimal"].ToString();
  
      MySqlCommand Sql2 = new MySqlCommand("SELECT * FROM town WHERE id ='" + idAnimal + "'", Connectio);
      MySqlDataReader dr2;
      dr2 = Sql2.ExecuteReader();
  
      while (dr2.Read())
      {
          dataGridView1.Rows.Add(dr2["number"], dr2["name"]);
      }
  
      dr2.Close();
  }
  
  dr1.Close();
  Connection.Close();
  </code></pre>