Creating queries using Criteria API (JPA 2.0)
- by Pym
Hello there !
I'm trying to create a query with the Criteria API from JPA 2.0, but I can't make it work.
The problem is with the "between" conditionnal method. I read some documentation to know how I have to do it, but since I'm discovering JPA, I don't understand why it does not work.
First, I can't see "creationDate" which should appear when I write "Transaction_."
I thought it was maybe normal, since I read the metamodel was generated at runtime, so I tried to use 'Foo_.getDeclaredSingularAttribute("value")' instead of 'Foo_.value', but it still doesn't work at all.
Here is my code :
public List<Transaction> getTransactions(Date startDate, Date endDate) {
EntityManager em = getEntityManager();
try {
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Transaction> cq = cb.createQuery(Transaction.class);
Metamodel m = em.getMetamodel();
EntityType<Transaction> Transaction_ = m.entity(Transaction.class);
Root<Transaction> transaction = cq.from(Transaction.class);
// Error here. cannot find symbol. symbol: variable creationDate
cq.where(cb.between(transaction.get(Transaction_.creationDate), startDate, endDate));
// I also tried this:
// cq.where(cb.between(Transaction_.getDeclaredSingularAttribute("creationDate"), startDate, endDate));
List<Transaction> result = em.createQuery(cq).getResultList();
return result;
} finally {
em.close();
}
}
Can someone help me to figure this out? Thanks.
