Hibernate query giving java.lang.IllegalArgumentException: node to traverse cannot be null

Question

This simple query

session = com.jthink.songlayer.hibernate.HibernateUtil.getSession();
Query q = session.createQuery("recNo from SongChanges");

giving this stacktrace

java.lang.IllegalArgumentException: node to traverse cannot be null!
    at org.hibernate.hql.internal.ast.util.NodeTraverser.traverseDepthFirst(NodeTraverser.java:63)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.parse(QueryTranslatorImpl.java:272)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:180)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:119)
    at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:214)
    at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:192)
    at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1537)

if I do

session = com.jthink.songlayer.hibernate.HibernateUtil.getSession();
Query q = session.createQuery("from SongChanges");

I dont get the error, but I only need the recNo

Any ideas ?

Answer 1

You forgot the select:

Query q = session.createQuery("select sc.recNo from SongChanges sc");

Answer 2

This error also commonly happens when you use the method createQuery to run a named query, instead of getNamedQuery, for example:

session.createQuery("InvoiceItem.itemsFromInvoice")

when the correct approach would be

session.getNamedQuery("InvoiceItem.itemsFromInvoice")