Examples with Fetch javax.persistence.criteria.Fetch used on opensource projects

Example 1 with Fetch

use of javax.persistence.criteria.Fetch in project hibernate-orm by hibernate.

the class QueryStructure method renderFetches.

@SuppressWarnings({ "unchecked" })
private void renderFetches(StringBuilder jpaqlQuery, RenderingContext renderingContext, Collection<Fetch> fetches) {
    if (fetches == null) {
        return;
    }
    for (Fetch fetch : fetches) {
        ((FromImplementor) fetch).prepareAlias(renderingContext);
        jpaqlQuery.append(renderJoinType(fetch.getJoinType())).append("fetch ").append(((FromImplementor) fetch).renderTableExpression(renderingContext));
        renderFetches(jpaqlQuery, renderingContext, fetch.getFetches());
    }
}

Example 2 with Fetch

use of javax.persistence.criteria.Fetch in project microservices by pwillhan.

the class Joins method executeQueries.

@Test
public void executeQueries() throws Exception {
    TestDataCategoriesItems testData = storeTestData();
    CriteriaBuilder cb = JPA.getEntityManagerFactory().getCriteriaBuilder();
    UserTransaction tx = TM.getUserTransaction();
    try {
        tx.begin();
        EntityManager em = JPA.createEntityManager();
        {
            // Implicit inner join
            CriteriaQuery criteria = cb.createQuery();
            Root<Bid> b = criteria.from(Bid.class);
            criteria.select(b).where(cb.like(b.get("item").<String>get("name"), "Fo%"));
            Query q = em.createQuery(criteria);
            List<Bid> result = q.getResultList();
            assertEquals(result.size(), 3);
            for (Bid bid : result) {
                assertEquals(bid.getItem().getId(), testData.items.getFirstId());
            }
        }
        em.clear();
        {
            // Multiple inner
            CriteriaQuery<Bid> criteria = cb.createQuery(Bid.class);
            Root<Bid> b = criteria.from(Bid.class);
            criteria.select(b).where(cb.equal(b.get("item").get("seller").get("username"), "johndoe"));
            Query q = em.createQuery(criteria);
            List<Bid> result = q.getResultList();
            assertEquals(result.size(), 4);
        }
        em.clear();
        {
            // Multiple inner
            CriteriaQuery criteria = cb.createQuery();
            Root<Bid> b = criteria.from(Bid.class);
            criteria.select(b).where(cb.and(cb.equal(b.get("item").get("seller").get("username"), "johndoe"), cb.isNotNull(b.get("item").get("buyNowPrice"))));
            Query q = em.createQuery(criteria);
            List<Bid> result = q.getResultList();
            assertEquals(result.size(), 3);
        }
        em.clear();
        {
            // Explicit inner
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            Join<Item, Bid> b = i.join("bids");
            criteria.select(i).where(cb.gt(b.<BigDecimal>get("amount"), new BigDecimal(100)));
            Query q = em.createQuery(criteria);
            List<Item> result = q.getResultList();
            assertEquals(result.size(), 1);
            assertEquals(result.get(0).getId(), testData.items.getFirstId());
        }
        em.clear();
        {
            // Explicit outer
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            Join<Item, Bid> b = i.join("bids", JoinType.LEFT);
            b.on(cb.gt(b.<BigDecimal>get("amount"), new BigDecimal(100)));
            criteria.multiselect(i, b);
            Query q = em.createQuery(criteria);
            List<Object[]> result = q.getResultList();
            assertEquals(result.size(), 3);
            assertTrue(result.get(0)[0] instanceof Item);
            assertTrue(result.get(0)[1] instanceof Bid);
            assertTrue(result.get(1)[0] instanceof Item);
            assertEquals(result.get(1)[1], null);
            assertTrue(result.get(2)[0] instanceof Item);
            assertEquals(result.get(2)[1], null);
        }
        em.clear();
        {
        // Explicit right outer
        /* TODO Right outer joins not supported in criteria, Hibernate bug JPA-2

                CriteriaQuery criteria = cb.createQuery();
                Root<Bid> b = criteria.from(Bid.class);
                Join<Bid, Item> i = b.join("item", JoinType.RIGHT);
                criteria.multiselect(b, i).where(
                   cb.or(
                      cb.isNull(b),
                      cb.gt(b.<BigDecimal>get("amount"), new BigDecimal(100)))
                );

                Query q = em.createQuery(criteria);
                List<Object[]> result = q.getResultList();
                assertEquals(result.size(), 2);
                assertTrue(result.get(0)[0] instanceof Bid);
                assertTrue(result.get(0)[1] instanceof Item);
                assertEquals(result.get(1)[0], null);
                assertTrue(result.get(1)[1] instanceof Item);
                */
        }
        em.clear();
        {
            // A typical "fetch the bids collections for all items as a side effect" query
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            i.fetch("bids", JoinType.LEFT);
            criteria.select(i);
            Query q = em.createQuery(criteria);
            List<Item> result = q.getResultList();
            // 3 items, 4 bids, 5 "rows" in result!
            assertEquals(result.size(), 5);
            // In-memory "distinct"
            Set<Item> distinctResult = new LinkedHashSet<Item>(result);
            // It was only three items all along...
            assertEquals(distinctResult.size(), 3);
            boolean haveBids = false;
            for (Item item : distinctResult) {
                // No more lazy loading!
                em.detach(item);
                if (item.getBids().size() > 0) {
                    haveBids = true;
                    break;
                }
            }
            assertTrue(haveBids);
        }
        em.clear();
        {
            // Hibernate can remove the duplicate SQL resultset rows for you
            // (...who knows, some of you actually WANT the duplicates!)
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            i.fetch("bids", JoinType.LEFT);
            criteria.select(i).distinct(true);
            Query q = em.createQuery(criteria);
            List<Item> result = q.getResultList();
            // Hibernate filtered it for us in-memory
            assertEquals(result.size(), 3);
            boolean haveBids = false;
            for (Item item : result) {
                // No more lazy loading!
                em.detach(item);
                if (item.getBids().size() > 0) {
                    haveBids = true;
                    break;
                }
            }
            assertTrue(haveBids);
        }
        em.clear();
        {
            // Fetch multiple associated instances/collections
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            Fetch<Item, Bid> b = i.fetch("bids", JoinType.LEFT);
            // These are non-nullable foreign key columns, inner join or
            b.fetch("bidder");
            // outer doesn't make a difference!
            i.fetch("seller", JoinType.LEFT);
            criteria.select(i).distinct(true);
            Query q = em.createQuery(criteria);
            List<Item> result = q.getResultList();
            assertEquals(result.size(), 2);
            boolean haveBids = false;
            boolean haveBidder = false;
            boolean haveSeller = false;
            for (Item item : result) {
                // No more lazy loading!
                em.detach(item);
                if (item.getBids().size() > 0) {
                    haveBids = true;
                    Bid bid = item.getBids().iterator().next();
                    if (bid.getBidder() != null && bid.getBidder().getUsername() != null) {
                        haveBidder = true;
                    }
                }
                if (item.getSeller() != null && item.getSeller().getUsername() != null)
                    haveSeller = true;
            }
            assertTrue(haveBids);
            assertTrue(haveBidder);
            assertTrue(haveSeller);
        }
        em.clear();
        {
            // SQL Cartesian product of multiple collections! Bad!
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            i.fetch("bids", JoinType.LEFT);
            // Cartesian product, bad!
            i.fetch("images", JoinType.LEFT);
            criteria.select(i).distinct(true);
            Query q = em.createQuery(criteria);
            List<Item> result = q.getResultList();
            assertEquals(result.size(), 3);
            boolean haveBids = false;
            boolean haveImages = false;
            for (Item item : result) {
                // No more lazy loading!
                em.detach(item);
                if (item.getBids().size() > 0)
                    haveBids = true;
                if (item.getImages().size() > 0)
                    haveImages = true;
            }
            assertTrue(haveBids);
            assertTrue(haveImages);
        }
        em.clear();
        {
            // Theta style inner join
            CriteriaQuery criteria = cb.createQuery();
            Root<User> u = criteria.from(User.class);
            Root<LogRecord> log = criteria.from(LogRecord.class);
            criteria.where(cb.equal(u.get("username"), log.get("username")));
            criteria.multiselect(u, log);
            Query q = em.createQuery(criteria);
            List<Object[]> result = q.getResultList();
            for (Object[] row : result) {
                assertTrue(row[0] instanceof User);
                assertTrue(row[1] instanceof LogRecord);
            }
            assertEquals(result.size(), 2);
        }
        em.clear();
        {
            // Theta style inner join, multiple
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            Root<Bid> b = criteria.from(Bid.class);
            criteria.where(cb.equal(b.get("item"), i), cb.equal(i.get("seller"), b.get("bidder")));
            criteria.multiselect(i, b);
            Query q = em.createQuery(criteria);
            List<Object[]> result = q.getResultList();
            assertEquals(result.size(), 0);
        }
        em.clear();
        {
            // Inner join with implicit ID comparison
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            Root<User> u = criteria.from(User.class);
            criteria.where(cb.equal(i.get("seller"), u), cb.like(u.<String>get("username"), "j%"));
            criteria.multiselect(i, u);
            Query q = em.createQuery(criteria);
            List<Object[]> result = q.getResultList();
            assertEquals(result.size(), 3);
            for (Object[] row : result) {
                assertTrue(row[0] instanceof Item);
                assertTrue(row[1] instanceof User);
            }
        }
        em.clear();
        {
            // Inner join with explicit ID comparison
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            Root<User> u = criteria.from(User.class);
            criteria.where(cb.equal(i.get("seller").get("id"), u.get("id")), cb.like(u.<String>get("username"), "j%"));
            criteria.multiselect(i, u);
            Query q = em.createQuery(criteria);
            List<Object[]> result = q.getResultList();
            assertEquals(result.size(), 3);
            for (Object[] row : result) {
                assertTrue(row[0] instanceof Item);
                assertTrue(row[1] instanceof User);
            }
        }
        em.clear();
        {
            // Binding an entity parameter
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            criteria.where(cb.equal(i.get("seller"), cb.parameter(User.class, "seller")));
            criteria.select(i);
            Query q = em.createQuery(criteria);
            User someUser = em.find(User.class, testData.users.getFirstId());
            q.setParameter("seller", someUser);
            List<Item> result = q.getResultList();
            assertEquals(result.size(), 2);
        }
        em.clear();
        {
            // Binding ID parameter
            CriteriaQuery criteria = cb.createQuery();
            Root<Item> i = criteria.from(Item.class);
            criteria.where(cb.equal(i.get("seller").get("id"), cb.parameter(Long.class, "sellerId")));
            criteria.select(i);
            Query q = em.createQuery(criteria);
            Long USER_ID = testData.users.getFirstId();
            q.setParameter("sellerId", USER_ID);
            List<Item> result = q.getResultList();
            assertEquals(result.size(), 2);
        }
        em.clear();
        {
            // Not a join, just ID comparison
            CriteriaQuery<Bid> criteria = cb.createQuery(Bid.class);
            Root<Bid> b = criteria.from(Bid.class);
            criteria.where(cb.equal(b.get("item").get("id"), cb.parameter(Long.class, "itemId")));
            criteria.select(b);
            Query q = em.createQuery(criteria);
            q.setParameter("itemId", testData.items.getFirstId());
            List<Bid> result = q.getResultList();
            assertEquals(result.size(), 3);
        }
        em.clear();
        tx.commit();
        em.close();
    } finally {
        TM.rollback();
    }
}

Example 3 with Fetch

use of javax.persistence.criteria.Fetch in project stdlib by petergeneric.

the class JPAQueryBuilder method addFetches.

private void addFetches(Collection<String> fetches) {
    Map<String, Fetch> created = new HashMap<>();
    for (String fetch : fetches) {
        Fetch parent = null;
        final String[] parts = StringUtils.split(fetch, '.');
        for (int i = 0; i < parts.length; i++) {
            final String path = StringUtils.join(parts, '.', 0, i + 1);
            Fetch existing = created.get(path);
            if (existing == null) {
                if (parent == null) {
                    // attribute of root
                    existing = root.fetch(parts[i], JoinType.LEFT);
                } else {
                    // attribute of parent
                    existing = parent.fetch(parts[i], JoinType.LEFT);
                }
                created.put(path, existing);
            }
            parent = existing;
        }
    }
}

Example 4 with Fetch

use of javax.persistence.criteria.Fetch in project tests by datanucleus.

the class CriteriaMetaModelTest method testResultCase.

/**
 * Test basic querying with a result including CASE expression.
 */
public void testResultCase() {
    EntityManager em = getEM();
    EntityTransaction tx = em.getTransaction();
    try {
        tx.begin();
        CriteriaBuilder cb = emf.getCriteriaBuilder();
        CriteriaQuery<Manager> crit = cb.createQuery(Manager.class);
        Root<Manager> candidate = crit.from(Manager.class);
        Set<Join<Manager, ?>> joins = candidate.getJoins();
        // Make sure joins returns empty set
        assertNotNull(joins);
        assertEquals(0, joins.size());
        Set<Fetch<Manager, ?>> fetches = candidate.getFetches();
        // Make sure fetches returns empty set
        assertNotNull(fetches);
        assertEquals(0, fetches.size());
        candidate.alias("m");
        Path<Integer> yrsVar = candidate.get(Manager_.yearsExperience);
        Predicate lessThan2 = cb.lessThan(yrsVar, 5);
        crit.multiselect(candidate.get(Manager_.firstName), candidate.get(Manager_.lastName), cb.selectCase().when(lessThan2, "Junior").otherwise("Senior"));
        // DN extension
        assertEquals("Generated JPQL query is incorrect", "SELECT m.firstName,m.lastName,CASE WHEN (m.yearsExperience < 5) THEN 'Junior' ELSE 'Senior' END FROM org.datanucleus.samples.jpa.query.Manager m", crit.toString());
        Query q = em.createQuery(crit);
        List<Object[]> results = q.getResultList();
        assertNotNull("Null results returned!", results);
        assertEquals("Number of results is incorrect", 2, results.size());
        boolean mourinho = false;
        boolean guardiola = false;
        Iterator<Object[]> resultIter = results.iterator();
        while (resultIter.hasNext()) {
            Object[] result = resultIter.next();
            assertEquals(3, result.length);
            if (result[0].equals("Jose") && result[1].equals("Mourinho")) {
                mourinho = true;
                assertEquals("Senior", result[2]);
            } else if (result[0].equals("Pep") && result[1].equals("Guardiola")) {
                guardiola = true;
                assertEquals("Junior", result[2]);
            }
        }
        if (!mourinho) {
            fail("Jose Mourinho not returned");
        }
        if (!guardiola) {
            fail("Pep Guardiola not returned");
        }
        tx.rollback();
    } finally {
        if (tx.isActive()) {
            tx.rollback();
        }
        em.close();
    }
}

Example 5 with Fetch

use of javax.persistence.criteria.Fetch in project tests by datanucleus.

the class CriteriaMetaModelTest method testResultTuple.

/**
 * Test basic querying with a result as a Tuple.
 */
public void testResultTuple() {
    EntityManager em = getEM();
    EntityTransaction tx = em.getTransaction();
    try {
        tx.begin();
        CriteriaBuilder cb = emf.getCriteriaBuilder();
        CriteriaQuery<Tuple> crit = cb.createTupleQuery();
        Root<Manager> candidate = crit.from(Manager.class);
        Set<Join<Manager, ?>> joins = candidate.getJoins();
        // Make sure joins returns empty set
        assertNotNull(joins);
        assertEquals(0, joins.size());
        Set<Fetch<Manager, ?>> fetches = candidate.getFetches();
        // Make sure fetches returns empty set
        assertNotNull(fetches);
        assertEquals(0, fetches.size());
        candidate.alias("m");
        crit.multiselect(candidate.get(Manager_.firstName), candidate.get(Manager_.lastName));
        // DN extension
        assertEquals("Generated JPQL query is incorrect", "SELECT m.firstName,m.lastName FROM org.datanucleus.samples.jpa.query.Manager m", crit.toString());
        Query q = em.createQuery(crit);
        List<Tuple> results = q.getResultList();
        assertNotNull("Null results returned!", results);
        assertEquals("Number of results is incorrect", 2, results.size());
        boolean mourinho = false;
        boolean guardiola = false;
        Iterator<Tuple> resultIter = results.iterator();
        while (resultIter.hasNext()) {
            Tuple result = resultIter.next();
            List<TupleElement<?>> tupleElements = result.getElements();
            assertEquals(2, tupleElements.size());
            Object elem0 = result.get(0);
            Object elem1 = result.get(1);
            assertTrue(elem0 instanceof String);
            assertTrue(elem1 instanceof String);
            String first = (String) elem0;
            String last = (String) elem1;
            if (first.equals("Jose") && last.equals("Mourinho")) {
                mourinho = true;
            } else if (first.equals("Pep") && last.equals("Guardiola")) {
                guardiola = true;
            }
        }
        if (!mourinho) {
            fail("Jose Mourinho not returned");
        }
        if (!guardiola) {
            fail("Pep Guardiola not returned");
        }
        tx.rollback();
    } finally {
        if (tx.isActive()) {
            tx.rollback();
        }
        em.close();
    }
}