ORA-06502 Error When Calling Function

Question

Hi,
We have upgraded Oracle Database Server 9i to 11.1.0.7 and we are now using ODP.NET version 2.112.2.0 instead of 9.2.0.4 dll.
After the migration, we encountered ORA-06502 problem when we are calling a function from .NET application. We investigated and found that we have to set the parameter size for the return value parameter (varchar2). But there is a strange case that how do we guess the return value size, it can be 5 characters or 5.000 characters. Before 11g Oracle.DataAccess, we do not have that such problem. We were setting the parameter size 225 by default, but ODP.NET was returning 500 characters without any error.
The question is that how do we guess or know the actual parameter size when we are passing a Return Value parameter to the function?
Or is there a solution for this behaviour of ODP.NET?
Thanks.

Answer 1

Is there a reason you can not set it to the default maximum size for a varchar2 of 32k?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Oracle.DataAccess.Client;
using System.Data;
namespace test_function2
class Program
static void Main(string[] args)
OracleConnection con = new OracleConnection("Data Source=UTF8;User ID=scott;Password=tiger");
OracleCommand cmd = new OracleCommand("test_return", con);
cmd.CommandType = CommandType.StoredProcedure;
OracleParameter test_return = new OracleParameter("test_return", OracleDbType.Varchar2, 32000);
test_return.Direction = ParameterDirection.ReturnValue;
cmd.Parameters.Add(test_return);
OracleParameter test_input = new OracleParameter("test_input", OracleDbType.Varchar2);
test_input.Direction = ParameterDirection.Input;
test_input.Value = "blah";
cmd.Parameters.Add(test_input);
try
con.Open();
cmd.ExecuteNonQuery();
con.Close();
Console.WriteLine("{0}", test_return.Value);
Console.WriteLine("Press Enter to Continue");
Console.ReadLine();
catch (OracleException e)
Console.WriteLine(e.Number);
Console.WriteLine(e.Message);
Console.WriteLine("test failed\nPress Enter to Continue");
Console.ReadLine();
create or replace function test_return(in_var in varchar2)
return varchar2 is
begin
return lpad(in_var, 4000, 'TEST test') || lpad(in_var, 4000, 'DONE done');
end test_return;
/