How do I call pl/sql function from Toplink

Question

I can easily call a stored procedure from Toplink
====================================================
public Collection executeSelectingStoredProcedure(StoredProcedureCall storedProcedureCall) throws DAOException
Collection returnValue = null;
Session session = null;
session = this.getSession();
returnValue = session.executeSelectingCall(storedProcedureCall);
session.release();
return returnValue;
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The same does not work for pl/sql functions. Doesnt Toplink treat function calls as a callable statement as in JDBC?
"select <function_name>(<arguments>) from dual" seems to be a work around. If this or using expressions is the only solution can someone please tell me the reasoning behind this shift.
Regards
Aamir Dehlavi

Answer 1

I have the same problem.
I have a PL/SQL function that returns a number. This function receives 2 parameters. I use StoredProcedureCall plus ValueReadQuery.
Session aSession = SessionManager.getManager().getDefaultSession();
StoredProcedureCall call = new StoredProcedureCall();
call.setProcedureName("CIO_UTILS.COUNT_USER_ROLES_IN_MODULE");
call.addNamedArgument("p_persid");
call.addNamedArgument("p_module");
call.addUnamedOutputArgument("rolesnum", Integer.class);
ValueReadQuery query = new ValueReadQuery();
//query.bindAllParameters();
query.setCall(call);
query.addArgument("p_persid");
query.addArgument("p_module");
Vector parameters = new Vector();
parameters.addElement(persid);
parameters.addElement(theModule);
Integer rolesnum = (Integer) aSession.executeQuery(query,parameters);
aSession.release();
if(rolesnum.intValue()<=0)return false; else return true;
However, I receive the following error:
Exception [TOPLINK-4002] (Oracle TopLink - 10g Release 3 (10.1.3.0.0) (Build 060118)): oracle.toplink.exceptions.DatabaseException
Internal Exception: java.sql.SQLException: ORA-06550: line 1, column 96:
PLS-00312: a positional parameter association may not follow a named association
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
Error Code: 6550
Call:BEGIN CIO_UTILS.COUNT_USER_ROLES_IN_MODULE(p_persid=>'SANCRA2791', p_module=>'PSL_MONITORING', ?); END;
     bind => [=> rolesnum]
If comment the line
"call.addUnamedOutputArgument("rolesnum", Integer.class);"
Toplink is trating it as a procedure, and I also receive an error from PL/SQL.
There should have to be a way of make it to receive the resoult somehow, but I do not know what.
Thanks in advance.