title: how to solve error "The given key was not present in the dictionary." when using data set with MySqlDataAdapter?
body: <p>I try to make connection with MySQL db  using this class.</p>
  
  <pre><code>public class DataManager
  {
      // Connection String
      public static string constr = ConfigurationManager.ConnectionStrings["cnn1"].ConnectionString; 
  
      public static DataSet GetDataSet(string stored_name, string table_name, params MySqlParameter[] prmarr)
      {
          MySqlConnection con = new MySqlConnection(constr);
          MySqlCommand cmd = new MySqlCommand(stored_name,con);
          cmd.CommandType = CommandType.StoredProcedure;
  
          foreach (MySqlParameter prm in prmarr)
          {
              cmd.Parameters.Add(prm);
          }
          DataSet ds = new DataSet();
          MySqlDataAdapter da = new MySqlDataAdapter(cmd);
  
          da.Fill(ds,table_name);
          return ds;
      } 
  </code></pre>
  
  <p>then I called it in load event of page that is inhered from master page</p>
  
  <pre><code>    protected void Page_Load(object sender, EventArgs e)
          {
              if (!IsPostBack)
              {  
           // product_select is stored procedure/ routine that I made it in db
                  using (DataSet ds = DataManager.GetDataSet("product_select","x")) // error is here
                  {
                      DataList1.DataSource = ds.Tables["x"];   
                      DataList1.DataBind();
                  }
              }
          }
  </code></pre>
  
  <p>when I run,I get this error.</p>
  
  <pre><code>An exception of type 'System.Collections.Generic.KeyNotFoundException' occurred in mscorlib.dll
  {"The given key was not present in the dictionary."}
  </code></pre>
  
  <p>my stored procedure in xampp db</p>
  
  <pre><code>DELIMITER $$
  CREATE DEFINER=`root`@`localhost` PROCEDURE `product_select`()
      NO SQL
  SELECT 'P_id','name','unit_price','image_product' FROM product$$
  DELIMITER ;
  </code></pre>