Urgent: ORA-24338: statement handle not executed

Question

Hello,
/*===================================================*/
PL/SQL code:
SQL> create or replace package p3 is
2 type t_c is ref cursor;
3 procedure p(p_c out t_c);
4 end p3;
5 /
Package created.
SQL> show errors;
No errors.
SQL>
SQL>
SQL> create or replace package body p3 is
2
3 procedure p(p_c out t_c)
4 is
5 v_c t_c;
6 begin
7 open v_c for
8 select job_number
9 from rep_adhoc_invoices
10 where rownum<5;
11 end p;
12 end p3;
13 /
Package body created.
SQL> show errors;
No errors.
/*===================================================*/
C# code:
OracleConnection dbConnection = null; /* see finalize{} */
OracleCommand dbCommand = null;
OracleDataAdapter dbAdapter = null;
try
     dbConnection = new OracleConnection(GetConnectionString());
     dbConnection.Open();
     dbCommand = new OracleCommand();
     dbCommand.Connection = dbConnection;
     dbCommand.CommandText = "p3.p";                    dbCommand.CommandType = CommandType.StoredProcedure;
     dbCommand.Parameters.Add("p_c", OracleDbType.RefCursor, DBNull.Value, ParameterDirection.Output);
     dbAdapter = new OracleDataAdapter(dbCommand);
     System.Data.DataSet ds = new DataSet();
     dbAdapter.Fill(ds);
     return(ds);
catch (Exception e)
     Console.WriteLine(e.Message);
/*===================================================*/
Problem:
When code executes:
dbAdapter.Fill(ds);
I constantly get the ORA-24338.
The same result if I try from console with "set autoprint on" (v_c is defined beforehand):
SQL> execute p3.p(:v_c)
PL/SQL procedure successfully completed.
ERROR:
ORA-24338: statement handle not executed
It seems to me, that the problem is on the server.
Does anyone know, WHAT is the problem?
Thanks a lot beforehand!
Edgar.

Answer 1

In your procedure implementation (below), you forgot to assign the local variable v_c to the out parameter p_c before exiting the rountine. This means that the ref cursor parameter is never opened.
The error you got occurs because when ODP.NET gets back the ref cursor it tries to fetch from it without checking whether it's open or not. If you look up the ORA-24338 error code in the documentation, it'll tell you as much. Typcially, when I get an error I don't understand, I head straight for the docs. They not only tell me what it means, but often suggest a solution.
This behaviour of ODP must be for performance reasons, since doing the check everytime would be wasted most of the time. Still, it would have been nice if they'd emulated MSDAORA, which DOES check.
3 procedure p(p_c out t_c)
4 is
5 v_c t_c;
6 begin
7 open v_c for
8 select job_number
9 from rep_adhoc_invoices
10 where rownum<5;
11 end p;
12 end p3;
13
Frankly, I'm surprised you didn't get ORA-3113: end of communication channel. This is what happened to me when I exited a function without assigning the ref cursor. To solve it, I'd changed the declaration of the PL/SQL function and OracleCommand parameters to IN OUT instead of just OUT. THEN, I got ORA-24338. Anyway, watch out for these things as you progress.
Happy coding.
Clarence