Implementing Try Catch Block RSS

• • Reply
  

  scriptkid

  Member

  30 Points

  21 Posts

  Implementing Try Catch Block

  Mar 03, 2012 08:13 AM|LINK

  Hi people.

  This is my code:

          public string district
          {
              get
              {
                  
  
  
                  String strConnString = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
  
                  String strQuery = "SELECT district FROM bankscombined WHERE ifsccode= '" + ifsccode + "'";
  
                  MySqlConnection con = new MySqlConnection(strConnString);
  
                  MySqlCommand cmd = new MySqlCommand();
  
                  cmd.CommandType = CommandType.Text;
  
  
                  cmd.Connection = con;
  
                  con.Open();
  
                  cmd.CommandText = strQuery;
  
  
                  MySqlDataReader sdr = cmd.ExecuteReader();
  
                  sdr.Read();
  
                  String dist = sdr["district"].ToString();
  
                  con.Close();
                  
                  return dist;
   
  
              }//end of get block
          } //end of district

  Now, What I am trying to do is, I passed a ifsccode which is not listed on the database.

  I am not understanding the way to implement the try & catch block. I tried to do this, but I failed.

  I am getting this error message currently without implementing the try & catch block:

  "Invalid attempt to access a field before calling Read()" pointing to the following line of the code:

  String dist = sdr["district"].ToString();

  Can anyone please provide me the soultion to this ?

  Thank you
  
  
  

  • Edited by scriptkid on Mar 03, 2012 08:15 AM
• • Reply
  

  karthicks

  All-Star

  31374 Points

  5420 Posts

  Re: Implementing Try Catch Block

  Mar 03, 2012 08:26 AM|LINK

  hi, before reading check whether data is there or not using below code

  if(dataReader.HasRows){

  sdr.Read();

  String dist = sdr["district"].ToString();
  }

  
   

  Thanks,
  Karthick S
• • Reply
  

  Mahesh Darku...

  Participant

  896 Points

  238 Posts

  Re: Implementing Try Catch Block

  Mar 03, 2012 08:30 AM|LINK

  check sdr["distinct"] is null or not

  if not null then only fillon the string ..i.e.
  

  String dist = sdr["district"].ToString();

  if it is work for you plz mark as answer..
• • Reply
  

  scriptkid

  Member

  30 Points

  21 Posts

  Re: Implementing Try Catch Block

  Mar 03, 2012 08:41 AM|LINK

  Thank you for your valuable replies.

  If i did that, I am unable to return the value to the variable district. The string variable dist goes out of scope.

  Check the screenshot.

  • Edited by scriptkid on Mar 03, 2012 08:43 AM
• • Reply
  

  karthicks

  All-Star

  31374 Points

  5420 Posts

  Re: Implementing Try Catch Block

  Mar 03, 2012 08:49 AM|LINK

  hi, check my updated code

  String dist="";
  if(dataReader.HasRows){

  sdr.Read();

  dist = sdr["district"].ToString();
  }
  return dist;

   

  Thanks,
  Karthick S
  • Marked as answer by scriptkid on Mar 03, 2012 09:29 AM
• • Reply
  

  scriptkid

  Member

  30 Points

  21 Posts

  Re: Implementing Try Catch Block

  Mar 03, 2012 09:29 AM|LINK

  Genius :D

  thanks :)