datareader fails but does not raise exception c#

Question

I am new to C# and I find some of the exception handling, or lack there of to be puzzling. I am trying to catch these exceptions but they are not caught I don't understand why. The code will cak after the exception and everything after the exception will be ignored, the next line executed will be a paint event for the form.

Obviously I can fix this example easily but I want to know why the exception is not raised. I have seen this quite a bit.

Here is an example:

public DataTable GetTaskDescription( string EstmateNameGuid)
    {
        string strJobNumName = null;

        MySqlCommand cmd = null;
        MySqlDataReader dr = null;
        MySqlConnection myconnection = new MySqlConnection(clsGlobeVar.localDB);
        myconnection.Open();
        DataTable table1 = new DataTable("EstGuids");

        string select = GetTaskDescription_SQLCreate();
        try
        {

            cmd = new MySqlCommand(select, myconnection);
            GetTaskDescription_ParameterFill(ref  cmd, clsGlobeVar.ClientGuid, EstmateNameGuid);

            dr = cmd.ExecuteReader();

            if (dr.HasRows)
            {                 
                table1.Columns.Add("Estimate_Guid");
                table1.Columns.Add("Estimate_Description");
                table1.Columns.Add("Estimate_Date");
                table1.Columns.Add("Active");
                string [] field = new string[5] ;

                while (dr.Read())
                {  
                    // going to read field in the row.
                    field[0] =  dr.SafeGetString(0);
                    field[1] =  dr.SafeGetString(1);
                    field[2] =  dr.SafeGetString(2);
                    field[3] =  dr.SafeGetString(3);
                      // this field does not exist but I tried to read it
                     // this should fail and raise an exception  
                     // it does fail but does not raise the exception
                    field[4] =  dr.SafeGetString(4);
                }
    }

   // this catch is ignored
catch (MySqlException ex)  
     {  some code }

// the finally block executes okay
finally  { some clean up}
// and this return statement is ignored and the code in the caller does not execute
return table1
}

Thanks for any help.

Answer 1

Handling exceptions in this way is generally not recommended, as you can never be sure what exceptions your nested code actually throws. You should at least add a handler for unexpected ones:

catch (MySqlException ex)  
 {  some code }
catch (Exception ex)
{
   //Unexpected exception thrown...
}