Jpql - multi expressions in select query, java.lang.ClassCastException:

Question

Hello, i'm trying to get a Unit object from the query below.
i am getting javax.ejb.EJBException in this method
@NamedQuery(name = "getUnitIdUnitName", query = "SELECT u.unitId,u.unitName FROM Unit u "+ "ORDER BY u.unitName")
public Unit getUnitsComboBox() {
//get UnitId, UnitName from Units.
Unit unitIDUnitName =(Unit) ((List<Object[]>)em.createNamedQuery("getUnitIdUnitName").getResultList()).get(0)[0];
return unitIDUnitName;
Caused by: java.lang.ClassCastException: java.lang.Long cannot be cast to mmis.entity.Unit
Must i use an iterator ?
Thanx

Answer 1

Amasoni wrote:
Hello, i'm trying to get a Unit object from the query below.
i am getting javax.ejb.EJBException in this method
@NamedQuery(name = "getUnitIdUnitName", query = "SELECT u.unitId,u.unitName FROM Unit u "+ "ORDER BY u.unitName")
public Unit getUnitsComboBox() {
//get UnitId, UnitName from Units.
Unit unitIDUnitName =(Unit) ((List<Object[]>)em.createNamedQuery("getUnitIdUnitName").getResultList()).get(0)[0];
return unitIDUnitName;
Caused by: java.lang.ClassCastException: java.lang.Long cannot be cast to mmis.entity.Unit
ThanxYou don't want to select the columns, you want to select the object itself.
SELECT u FROM Unit u ORDER BY u.unitName
or even shorter:
FROM Unit u ORDER BY u.unitName
Try to reason where to put your question by the way, it is not about Javaserver Faces. If you can't find a forum that clearly matches consider putting it in Java Programming. In this case it was entirely unnecessary since you already posted JPA questions in the EJB forum, which is a decent match.