Select * from table using jpa criteria not working properly

Question

I'm using jpa criteria for my select clause. I'm not able to get the result set. Here is my code

CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Object[]> cq = cb.createQuery(Object[].class);
Root<PKEntity> root = cq.from(PKEntity.class);
List<Object[]> resultlist = em.createQuery(cq).getResultList();

It throws the following error

No terms is selected for criteria query. Use CriteriaQuery.select or multiselect.

What I'm doing wrong here? I'm using my mobile to post.. so I'm sorry I could nt post the whole stacktrace

Utku Soytaş · Answer 1 · 2016-12-19T09:46:41.683

0

Your cq.select function is missing. Add

cq.select(what do you want);

after then

Root<PKEntity> root = cq.from(PKEntity.class);

edited Dec 19 '16 at 09:46

answered Dec 19 '16 at 09:43

Utku Soytaş

1,475
2
19
30

Can you plz post the total snippet? I just want a query like select * from my entity table – Syed Dec 19 '16 at 09:45
cq.select(cb.array(root.get(PKEntity.column_name)); or cq.select(root) for all columns – Utku Soytaş Dec 19 '16 at 09:50
1. There is no columns If I use .class it's throwing me error at .get as it's not applicable – Syed Dec 19 '16 at 09:52
Review this link and iplement for you https://wiki.eclipse.org//UserGuide/JPA/Basic_JPA_Development/Querying/Criteria#Constructors – Utku Soytaş Dec 19 '16 at 09:57

score 0 · Answer 2 · answered Dec 19 '16 at 09:56

0

try adding Restriction in your criteria. Restriction is basically similar to a "Where" clause.

answered Dec 19 '16 at 09:56

Nabarun Dey

104
9

Solved by using http://stackoverflow.com/questions/9793252/selecting-all-rows-from-a-database-using-jpa-in-websphere – Syed Dec 19 '16 at 10:01
Yes! Same approach with me @ benny 's answer – Utku Soytaş Dec 19 '16 at 10:13
except that "Restriction" is part of Hibernate Criteria and the user is using JPA Criteria ... – Neil Stockton Dec 19 '16 at 10:49

score 0 · Answer 3 · answered Dec 19 '16 at 10:28

public List<Object[]> loadAllObj() {
    CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
    CriteriaQuery<Object[]> query = criteriaBuilder .createQuery(Object[].class);
    Root<PKEntity> variableRoot = query.from(PKEntity.class);
    query.select(variableRoot);
    return em.createQuery(query).getResultList();
}

Select * from table using jpa criteria not working properly

3 Answers3