Adam Bien's Weblog

Selecting All JPA Entities As Criteria Query

You could define a NamedQuery "SELECT c FROM ConfigurationEntry c" or use a type safe criteria variant in JPA 2+:


    @PersistenceContext
    EntityManager em;


 public List<ConfigurationEntry> allEntries() {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<ConfigurationEntry> cq = cb.createQuery(ConfigurationEntry.class);
        Root<ConfigurationEntry> rootEntry = cq.from(ConfigurationEntry.class);
        CriteriaQuery<ConfigurationEntry> all = cq.select(rootEntry);
        TypedQuery<ConfigurationEntry> allQuery = em.createQuery(all);
        return allQuery.getResultList();
    }

This post is bit selfish: now I have a cheat sheet to lookup the first three lines. I just cannot remember these.

See you at Java EE Workshops at MUC Airport!

The snippet was stolen from: https://github.com/AdamBien/e2ftp


NEW workshop: Java EE 7 and Java 8, January 27th, 2015, Airport Munich

A book about rethinking Java EE Patterns

Comments:

This is really too verbose

Posted by Solerman Kaplon on August 08, 2013 at 07:44 PM CEST #

Perfect! Now we just have to get back to be paid in lines of code… :)

Posted by Oliver Gierke on August 09, 2013 at 03:28 PM CEST #

This is why CriteriaQuery need some simplify...

Posted by airborn on August 11, 2013 at 02:43 AM CEST #

Great!
Exactly what I needed.
Thanks for sharing.
@airborn:

put this method in an abstract Facade of your Entities and let your EntityFacade inherit.

Type once and never again.
I don't even have to remember this post, Adam ;-)

Posted by superwese on November 09, 2013 at 04:12 AM CET #

Is there anything wrong with:

CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Party> cq = cb.createQuery(Party.class);
TypedQuery<Party> allQuery = em.createQuery(cq);
List<Party> parties = allQuery.getResultList();

Posted by Karl on December 02, 2013 at 05:04 AM CET #

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