本文整理了Java中javax.persistence.criteria.CriteriaQuery.from()方法的一些代码示例，展示了CriteriaQuery.from()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。CriteriaQuery.from()方法的具体详情如下：
包路径：javax.persistence.criteria.CriteriaQuery
类名称：CriteriaQuery
方法名：from

CriteriaQuery.from介绍

暂无

代码示例

代码示例来源：origin: spring-projects/spring-data-examples

public List<User> myCustomBatchOperation() {

    CriteriaQuery<User> criteriaQuery = em.getCriteriaBuilder().createQuery(User.class);
    criteriaQuery.select(criteriaQuery.from(User.class));
    return em.createQuery(criteriaQuery).getResultList();
  }
}

代码示例来源：origin: rapidoid/rapidoid

public <T> Results<T> of(Class<T> clazz) {
  CriteriaQuery<T> query = cb().createQuery(clazz);
  query.from(clazz);
  return find(query);
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
public void test_criteria_from_root_example() {
  doInJPA( this::entityManagerFactory, entityManager -> {
    //tag::criteria-from-root-example[]
    CriteriaBuilder builder = entityManager.getCriteriaBuilder();
    CriteriaQuery<Person> criteria = builder.createQuery( Person.class );
    Root<Person> root = criteria.from( Person.class );
    //end::criteria-from-root-example[]
  });
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public Long readNumberOfAddresses() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Long> criteria = builder.createQuery(Long.class);
  criteria.select(builder.count(criteria.from(CustomerAddressImpl.class)));
  TypedQuery<Long> query = em.createQuery(criteria);
  return query.getSingleResult();
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public Long readNumberOfOrderItems() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Long> criteria = builder.createQuery(Long.class);
  criteria.select(builder.count(criteria.from(OrderItemImpl.class)));
  TypedQuery<Long> query = em.createQuery(criteria);
  return query.getSingleResult();    }

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
  public Long readNumberOfOrders() {
     CriteriaBuilder builder = em.getCriteriaBuilder();
     CriteriaQuery<Long> criteria = builder.createQuery(Long.class);
     criteria.select(builder.count(criteria.from(OrderImpl.class)));
     TypedQuery<Long> query = em.createQuery(criteria);
     return query.getSingleResult();
  }
}

代码示例来源：origin: rapidoid/rapidoid

public long count(Class<?> clazz) {
  CriteriaBuilder cb = em.getCriteriaBuilder();
  CriteriaQuery<Long> cq = cb.createQuery(Long.class);
  cq.select(cb.count(cq.from(clazz)));
  return em.createQuery(cq).getSingleResult();
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
  public Long readNumberOfCustomers() {
    CriteriaBuilder builder = em.getCriteriaBuilder();
    CriteriaQuery<Long> criteria = builder.createQuery(Long.class);
    criteria.select(builder.count(criteria.from(CustomerImpl.class)));
    TypedQuery<Long> query = em.createQuery(criteria);

    return query.getSingleResult();
  }
}

代码示例来源：origin: spring-projects/spring-data-examples

@Override
  public void removedExpiredAccounts(LocalDate reference) {

    CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<Account> query = cb.createQuery(Account.class);
    Root<Account> account = query.from(Account.class);

    query.where(cb.lessThan(account.get("expiryDate").as(Date.class), reference.toDateTimeAtStartOfDay().toDate()));

    for (Account each : em.createQuery(query).getResultList()) {
      em.remove(each);
    }
  }
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public List<PageField> readPageFieldsByPageId(Long pageId) {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<PageField> criteria = builder.createQuery(PageField.class);
  Root<PageFieldImpl> pageField = criteria.from(PageFieldImpl.class);
  criteria.select(pageField);
  Path<Object> path = pageField.get("page").get("id");
  criteria.where(builder.equal(pageField.get("page").get("id"), pageId));
  TypedQuery<PageField> query = em.createQuery(criteria);
  query.setHint(QueryHints.HINT_CACHEABLE, true);
  return query.getResultList();
}

代码示例来源：origin: stackoverflow.com

CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery cq = cb.createQuery(Employee.class);
Root emp = cq.from(Employee.class);
 <b>
 <i>
  Path<List<Project>>
 </i>
 </b>
 projects = emp.get("projects"));
cq.where(cb.isEmpty(projects);
cq.select(emp);

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public Long countAllowedValuesForProductOptionById(Long productOptionId) {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Long> criteria = builder.createQuery(Long.class);
  Root<ProductOptionValueImpl> root = criteria.from(ProductOptionValueImpl.class);
  criteria.select(builder.count(root));
  List<Predicate> restrictions = new ArrayList<>();
  List<Long> mergedIds = sandBoxHelper.mergeCloneIds(ProductOptionImpl.class, productOptionId);
  restrictions.add(root.get("productOption").in(mergedIds));
  criteria.where(restrictions.toArray(new Predicate[restrictions.size()]));
  TypedQuery<Long> query = em.createQuery(criteria);
  return query.getSingleResult();
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public List<StructuredContent> findAllContentItems() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<StructuredContent> criteria = builder.createQuery(StructuredContent.class);
  Root<StructuredContentImpl> sc = criteria.from(StructuredContentImpl.class);
  criteria.select(sc);
  try {
    TypedQuery<StructuredContent> query = em.createQuery(criteria);
    query.setHint(QueryHints.HINT_CACHEABLE, true);
    return query.getResultList();
  } catch (NoResultException e) {
    return new ArrayList<StructuredContent>();
  }
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public Customer readCustomerByExternalId(String id) {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Customer> criteria = builder.createQuery(Customer.class);
  Root<? extends Customer> customer = criteria.from(entityConfiguration.lookupEntityClass(Customer.class.getName(), Customer.class));
  criteria.select(customer);
  criteria.where(builder.equal(customer.get("externalId"), id));
  TypedQuery<Customer> query = em.createQuery(criteria);
  query.setHint(QueryHints.HINT_CACHEABLE, false);
  query.setHint(QueryHints.HINT_CACHE_REGION, "query.Customer");
  List<Customer> resultList = query.getResultList();
  return CollectionUtils.isEmpty(resultList) ? null : resultList.get(0);
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public List<URLHandler> findAllURLHandlers() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<URLHandler> criteria = builder.createQuery(URLHandler.class);
  Root<URLHandlerImpl> handler = criteria.from(URLHandlerImpl.class);
  criteria.select(handler);
  TypedQuery<URLHandler> query = em.createQuery(criteria);
  query.setHint(QueryHints.HINT_CACHEABLE, true);
  try {
    return query.getResultList();
  } catch (NoResultException e) {
    return new ArrayList<URLHandler>();
  }
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public List<Page> readAllPages() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Page> criteria = builder.createQuery(Page.class);
  Root<PageImpl> page = criteria.from(PageImpl.class);
  criteria.select(page);
  try {
    Query query = em.createQuery(criteria);
    query.setHint(QueryHints.HINT_CACHEABLE, true);
    return query.getResultList();
  } catch (NoResultException e) {
    return Collections.emptyList();
  }
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public List<PageTemplate> readAllPageTemplates() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<PageTemplate> criteria = builder.createQuery(PageTemplate.class);
  Root<PageTemplateImpl> template = criteria.from(PageTemplateImpl.class);
  criteria.select(template);
  try {
    Query query = em.createQuery(criteria);
    query.setHint(QueryHints.HINT_CACHEABLE, true);
    return query.getResultList();
  } catch (NoResultException e) {
    return Collections.emptyList();
  }
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public List<Translation> readTranslations(TranslatedEntity entity, String entityId, String fieldName) {
  entityId = getUpdatedEntityId(entity, entityId);
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Translation> criteria = builder.createQuery(Translation.class);
  Root<TranslationImpl> translation = criteria.from(TranslationImpl.class);
  criteria.select(translation);
  criteria.where(builder.equal(translation.get("entityType"), entity.getFriendlyType()),
    builder.equal(translation.get("entityId"), entityId),
    builder.equal(translation.get("fieldName"), fieldName)
  );
  TypedQuery<Translation> query = em.createQuery(criteria);
  query.setHint(QueryHints.HINT_CACHEABLE, true);
  return query.getResultList();
}

代码示例来源：origin: BroadleafCommerce/BroadleafCommerce

@Override
public Long readTotalStaticAssetCount() {
  CriteriaBuilder builder = em.getCriteriaBuilder();
  CriteriaQuery<Long> criteria = builder.createQuery(Long.class);
  criteria.select(builder.count(criteria.from(StaticAssetImpl.class)));
  TypedQuery<Long> query = em.createQuery(criteria);
  query.setHint(QueryHints.HINT_CACHEABLE, true);
  return query.getSingleResult();
}

代码示例来源：origin: kiegroup/jbpm

@Override
public Long findTaskIdByContentId( Long contentId ) {
  check();
  CriteriaBuilder builder = this.em.getCriteriaBuilder();
  CriteriaQuery<Long> query = builder.createQuery(Long.class);
  Root<TaskImpl> taskRoot = query.from(TaskImpl.class);
  Root<ContentImpl> contentRoot = query.from(ContentImpl.class);
  query.select(taskRoot.get(TaskImpl_.id));
  Predicate taskContentJoinPred = builder.equal(
      contentRoot.get(ContentImpl_.id),
      taskRoot.get(TaskImpl_.taskData).get(TaskDataImpl_.outputContentId));
  Predicate contentIdPred = builder.equal(
      contentRoot.get(ContentImpl_.id),
      contentId);
  query.where(builder.and(taskContentJoinPred, contentIdPred));
  Query choppedLiver = em.createQuery(query);
  return (Long) choppedLiver.getSingleResult();
}