How to return only one column in Hibernate?

Question

I want to return only one column from table. This is my DAO:

@SuppressWarnings("unchecked")
    public String getUri() {

        return sessionFactory.getCurrentSession()
                .createQuery("uri from Templates WHERE state=1").toString();
    }

Uri is a column. Domain:

    public String getUri() {
        return uri;
    }

    public void setUri(String uri) {
        this.uri = uri;
    }

Console says:

 Request processing failed; nested exception is java.lang.IllegalArgumentException: node to traverse cannot be null!

The second version:

@SuppressWarnings("unchecked")
    public String getUri() {

        return (String) sessionFactory.getCurrentSession()
                .createQuery("select uri from TEMPLATES WHERE state=1")
                .uniqueResult();
    }

Console:

Request processing failed; nested exception is org.hibernate.hql.ast.QuerySyntaxException: TEMPLATES is not mapped [select uri from TEMPLATES WHERE state=1]

I think you forgot to call `getResultList()` or `list` on Query object. And return `List — Wirus, Aug 08 '13 at 14:39

Amin Abu-Taleb · Accepted Answer · 2013-08-08T14:50:30.580

1

Your SELECT clause is missing:

@SuppressWarnings("unchecked")
    public String getUri() {

        Query q = sessionFactory.getCurrentSession()
                .createQuery("SELECT uri FROM Templates WHERE state=1");

        List l = q.list();

        //guess you know there's only one result?
        return l.get(0).toString();
    }

More info in: https://forum.hibernate.org/viewtopic.php?p=2448422

edited Aug 08 '13 at 14:50

answered Aug 08 '13 at 14:40

Amin Abu-Taleb

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Look at the topic please – John Smith Aug 08 '13 at 14:45
Really? Is this 'accepted' answer? It just returns query string instead of query result. – Wirus Aug 08 '13 at 14:50
Yeah, lol, accepted before correct version was introduced according to my answer and comment. – Wirus Aug 08 '13 at 14:53

score 0 · Answer 2 · answered Aug 08 '13 at 13:52

0

You need to use the class/field names, not the table/column names. Also, the query won't return a list of instances of your class for that table, but rather an array. Also, put a select in your query. I believe that exception means your hql is broken.

answered Aug 08 '13 at 13:52

hvgotcodes

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But uri - is field name. Look. – John Smith Aug 08 '13 at 14:30
Now it says:`TEMPLATES is not mapped [select uri from TEMPLATES WHERE state=1]` – John Smith Aug 08 '13 at 14:40
@John, if you still have this problem, see http://stackoverflow.com/questions/8524767/hibernate-throws-strange-error-class-is-not-mapped – Wirus Aug 08 '13 at 14:48

Wirus · Answer 3 · 2013-08-08T14:51:33.047

0

As you added select, then call list method on your Query. And get first result from the list if you want to get only first one.

edited Aug 08 '13 at 14:51

answered Aug 08 '13 at 14:42

Wirus

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How to return only one column in Hibernate?

3 Answers3