JavaDB or Toplink not recognizing named parameters?

Question

Creating a query within a session bean but the named parameter is causing an exception. Using Derby with Toplink in the Sun App Server 9.0_01. Any ideas what the problem or solution is?
    public String getNumberOfInvoices(String supplierAccount) {
        String suppAcc = "";
        Query qry = em.createNativeQuery(
                "select count(d) from App.Documents as d " +
                "where d.PERSONALACCOUNT = :suppAcc;");
        qry.setParameter("suppAcc", supplierAccount);
        Long count = (Long) qry.getSingleResult();
        return Long.toString(count);
[#|2007-09-22T23:41:09.271+0100|WARNING|sun-appserver-pe9.0|oracle.toplink.essentials.file:/C:/Sun/SDK/domains/domain1/applications/j2ee-apps/Accounting/Accounting-ejb_jar/-Accounting-ejbPU|_ThreadID=16;_ThreadName=httpWorkerThread-8080-1;_RequestID=4ffb3c50-34f3-42cf-a00b-26e93a0f8ed6;|
Local Exception Stack:
Exception [TOPLINK-4002] (Oracle TopLink Essentials - 2006.8 (Build 060830)): oracle.toplink.essentials.exceptions.DatabaseException
Internal Exception: org.apache.derby.client.am.SqlException: Syntax error: Encountered ":" at line 1, column 67.Error Code: -1
Call:select count(d) from App.Documents as d where d.PERSONALACCOUNT = :suppAcc;
Query:DataReadQuery()
     at oracle.toplink.essentials.exceptions.DatabaseException.sqlException(DatabaseException.java:303)
     at oracle.toplink.essentials.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:551)
     at oracle.toplink.essentials.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:437)
     at oracle.toplink.essentials.threetier.ServerSession.executeCall(ServerSession.java:465)
     at oracle.toplink.essentials.internal.queryframework.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:213)
     at oracle.toplink.essentials.internal.queryframework.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:199)

Answer 1

This seems to have resolved the problem to a degree. I am not sure why
numeric parameters are accepted but named one are not. I don't know. I can do named parameters with Hibernate. I don't know TopLink.
You understand that "named query" is different from "query with named parameters", right? You seem to want the latter, not the former. Maybe you're reading the wrong docs.
I have also
changed from count(d) to count(*). Is this because I am using EJB Query
Language but createNativeQuery is plain JDBC?
If you're counting all the rows in a table, it would be count(*). If you want to only count certain rows, it'd be a GROUP BY and HAVING.
Any way the error is now saying:-
Caused by: java.lang.ClassCastException: java.util.Vector cannot be cast
to java.lang.Long
This is pretty clear. You're assuming that the method returns a Long and it's telling you that it returns a Vector. It should only have size 1, and you should get the zeroth index value out of it.
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