Using union command in jsp

Question

i have my select statement in my jsp like this....
<sql:query dataSource="${conn}" var="kur">
select ka_kod_sesi_semester sem,
ka_kod_kursus kursus,
BK_NAMA_KURSUS nama_kursus
from akd.kursus_ambil,
akd.bank_kursus,
akd.pelajar
where ka_no_matrik=pel_no_matrik
and pel_no_matrik=?
and ka_kod_kursus=bk_kod_kursus
union
select kur_sej.ka_kod_sesi_semester sem,
kur_sej.ka_kod_kursus kursus,
BK_NAMA_KURSUS nama_kursus
from akd.kursus_ambil_sejarah kur_sej,
akd.bank_kursus,
akd.pelajar
where kur_sej.ka_no_matrik=pel_no_matrik
and pel_no_matrik=?
and kur_sej.ka_kod_kursus=bk_kod_kursus
order by ka_kod_sesi_semester,
ka_kod_kursus
<sql:param value="${param.ID}"/>
<%-- <sql:param value="${param.ID}"/> --%>
</sql:query>
<%--
Create an KursusBean and save it in
the session scope and redirect to the appropriate page.
--%>
<c:set var="kurValues" value="${kur.rows[0]}"/>
<jsp:useBean id="kurPel" scope="session" class="beans.pelajar.KursusBean">
<c:set target="${kurPel}" property="sem" value="${kurValues.sem}"/>
<c:set target="${kurPel}" property="kursus" value="${kurValues.kursus}"/>
<c:set target="${kurPel}" property="namaKursus" value="${kurValues.nama_kursus}"/>
</jsp:useBean>
but when i runnig this page, i will get this error...
: ORA-00904: "KA_KOD_SESI_SEMESTER": invalid identifier
i'm using oracle 9i database....
which the best method
1) select statement in java bean
2) select statement in jstl
pls...help me

Answer 1

The cause of the ORA-00904 is "The column name entered is either missing or invalid". Check your SQL queries and see if all your column names are correct.
HTH