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

Question

In my hibernate query I have :

public void updateStudent(Student student) {


        String hql = "update Student set article =:null,id=2" 
                +"where article=:"+ student.getArticle();

        sessionFactory.getCurrentSession().createQuery(hql);

    }

Here I want to set student table's article value= null and id =2 ..but

every time an error is occurring:
 node to traverse cannot be null!
Caused by:

java.lang.IllegalArgumentException: node to traverse cannot be null!

my actual mysql query is:

UPDATE student
SET article='null', id=2
WHERE article='xyz';  here xyz=user.getArticle()

what am I doing wrong??

Answer 1

As @JBNizet mentions in the comment, you need to consult the documentation. But you need something like this to set your parameter.

public void updateStudent(Student student) {
    String hql = "update Student set article = null, id = 2" 
        + " where article = :article";

    sessionFactory.getCurrentSession()
        .createQuery(hql)
        .setParameter("article", student.getArticle()) ... etc

}

PS I cannot understand why you are setting the id of your Student when you appear to be deleting an article value.