Call function with DML

Question

I have a function that performs DML. I am calling the function from toplink with the following. I get an error
ORA-14551: cannot perform a DML operation inside a query when I try to execute this function. Is there another way to call functions without using select From dual?
String queryFunc = "SELECT " +
"CCU.adjPaymentTrans(#caseID, #obligorPIN, #ccuPIN, #transCd, #payorTp) " +
"FROM dual";
SQLCall sqlCallFunc = new SQLCall(queryFunc);
ValueReadQuery valueReadFunc = new ValueReadQuery(sqlCallFunc);
valueReadFunc.addArgument("caseID");
valueReadFunc.addArgument("obligorPIN");
valueReadFunc.addArgument("ccuPIN");
valueReadFunc.addArgument("transCd");
valueReadFunc.addArgument("payorTp");
valueReadFunc.bindAllParameters();
Vector theArgumentValuesFunc = new Vector(6);
theArgumentValuesFunc.add(caseID);
theArgumentValuesFunc.add(obligorPIN);
theArgumentValuesFunc.add(ccuPIN);
theArgumentValuesFunc.add(transCd);
theArgumentValuesFunc.add(payorTp);
Number amountReversed = (Number)uow.executeQuery(valueReadFunc, theArgumentValuesFunc);

Answer 1

Normally DML is only done from stored procedures, not stored functions, you may want to consider changing the function to a procedure.
To call a function that does DML, you must call the function through a PLSQL call. If you did not require the return value, the code would be:
>>
String queryFunc = "begin " +
"CCU.adjPaymentTrans(#caseID, #obligorPIN, #ccuPIN, #transCd, #payorTp);" +
"end;";
SQLCall sqlCallFunc = new SQLCall(queryFunc);
DataModifyQuery modifyFunc = new DataModifyQuery(sqlCallFunc);
>>
If you require the return value, then the SQL would be:
>>
String queryFunc = "begin ? = " +
"CCU.adjPaymentTrans(?, ?, ?, ?, ?);" +
"end;";
>>
However this would have to be executed through a CallableStatement in JDBC. TopLink currently only supports executing stored procedures as callable statements, so you would need to execute this directly through JDBC. You could also convert the function to a procedure, or wrap the function with a procedure. I believe TopLink 10.1.3 will have support for a StoredFunctionCall that can call DML stored functions.
To get a JDBC connection from a TopLink session uses,
UnitOfWork uow = session.acquireUnitOfWork();
uow.beginEarlyTransaction()
uow.getAccessor().getConnection();
uow.commit();