title: "There is already an open DataReader associated with this Command which must be closed first."
body: <p>I'm working on application which needs to connect to another database to get some data,
   and to do that, I decided to use SqlConnection, reader etc..</p>
  
  <p>And I need to execute few queries, for example first I need to get CARD ID for some user, after that I need to get some data by that CARD ID..</p>
  
  <p>Here is my code:</p>
  
  <pre><code>#region Connection to another Database
  
  SqlConnection sqlConnection1 = new SqlConnection("Data Source=ComputerOne; Initial Catalog=TestDatabase;Integrated Security=False; User ID=test; Password=test123;");
  SqlCommand cmd = new SqlCommand();
  SqlDataReader reader;
  
  cmd.CommandText = "Select * From Users Where CardID=" + "'" + user.CardID + "'";
  cmd.CommandType = CommandType.Text;
  cmd.Connection = sqlConnection1;
  
  sqlConnection1.Open();
  
  reader = cmd.ExecuteReader();
  
  string cardID = "";
  string quantity="";
  
  while (reader.Read())
  {
      cardID = reader["CardID"].ToString();
  }
  //HOW COULD I WRITE ANOTHER QUERY NOW, FOR EXAMPLE, OK I GOT CARDID NOW GIVE ME SOME OTHER THINGS FROM THAT DATABASE BY THAT cardID
  //here I tried to change CommandText and to keep working with reader.. but its not working like this because its throwing me exception mention in question title.
  
  cmd.CommandText = "Select T1.CardID, T2.Title, Sum(T1.Quantity) as Quantity From CardTransactions as T1 JOIN Adds as T2 ON T1.AddsID = T2.AddsID Where T1.CardID =" + cardID + "AND T1.Type = 1 Group By T1.CardID, T2.Title";
  
  reader = cmd.ExecuteReader();
  
  while (reader.Read())
  {
      quantity = reader["Quantity"].ToString();
  }
  
  // Data is accessible through the DataReader object here.
  
  sqlConnection1.Close();
  
  #endregion 
  </code></pre>
  
  <p>So guys how could I execute few queries statemens using this example.</p>
  
  <p>Thanks a lot!
  Cheers</p>