# ORM

List<String> taskLists = new ArrayList<>();
taskLists.addAll(tasksToArchive);
int times = tasksToArchive.size() % 1000 == 0 ? tasksToArchive.size() / 1000 : (tasksToArchive.size() / 1000 + 1);
List<IAccountingTask> tasksToArchiveList = new ArrayList<IAccountingTask>();
if (taskLists != null && !taskLists.isEmpty()) {
    for (int i = 0; i < times; i++) {
        List<? extends IAccountingTask> tempList;
        if ((i + 1) * 1000 <= taskLists.size()) {
            tempList = persistenceManager.getSession().getAll(AccountingTask.class,
                    taskLists.subList(i * 1000, (i + 1) * 1000));
        } else {
            tempList = persistenceManager.getSession().getAll(AccountingTask.class,
                    taskLists.subList(i * 1000, taskLists.size()));
        }
        tasksToArchiveList.addAll(tempList);
    }
}

List<TransactRepViewModel> result = new ArrayList<TransactRepViewModel>();
final List<List<String>> partitions = ListUtils.partition(clientIdList, 999);
for (List<String> partition : partitions) {
    result.addAll(yourRepo.findByClientIdList(partition, startDate, endDate);)
}
 
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session.createsqlquery("select name ,age,birthday from students") .setresulttransformer(transformers.aliastobean(students.class)) 
// 或
setresulttransformer(new aliastobeanresulttransformer (students.class)) 
 
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List<Map<String, Object>> list = session.createSQLQuery(sql).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP).list();
Map<String, Object> map = (Map<String, Object>) session.createSQLQuery(sql).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP).uniqueResult();
 
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Double result = (Double) session.createSQLQuery(querySql).uniqueResult();
 
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String hql = "from Invest i where i.loan.id=? and i.status=?";
List<Invest> is = ht.find(hql, new String[] { loanId, InvestStatus.REPAYING });
// 或者
String hql = "from Invest i where i.loan.id=? and i.status=?";
List<Invest> is = ht.find(hql, loanId, InvestStatus.REPAYING );

// 使用in，同createSQLQuery使用方式一样
String hql = "from Invest i where i.loan.id=? and i.status in(:status)";
List<Invest> is = session.createQuery(sql)
					.setParameter(0, loanId)
					.setParameterList("status", Arrays.asList(InvestStatus.REPAYING, InvestStatus.OVERDUE,
							InvestStatus.COMPLETE, InvestStatus.BID_SUCCESS)).list()
 
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// Restrictions.in传值为数组或list集合
List<String> status = Arrays.asList(InvestConstants.InvestStatus.REPAYING,InvestConstants.InvestStatus.OVERDUE);
DetachedCriteria criteria = DetachedCriteria.forClass(InvestExtensionPlan.class);
criteria.createAlias("invest", "i");// 当查询关联第三张表时，第二张表需要取别名
criteria.add(Restrictions.eq("i.loan.id", loanExtensionPlan.getLoan().getId()));
criteria.add(Restrictions.in("status", status)); // 可解决ORACLE in 大于1000问题
criteria.addOrder(Order.desc("period"));// 添加排序

// 查询一范围内的的数据,需借助Criteria来查询
Criteria cri = criteria.getExecutableCriteria(ht.getSessionFactory().getCurrentSession());
cri.setFirstResult(firstResult);// 从第几条开始
cri.setMaxResults(maxResults);// 查询多少条
List<InvestExtensionPlan> investExtensionPlans = ht.findByCriteria(criteria);


// 可解决ORACLE in 大于1000问题
private void addCriteriaIn(String propertyName, List<?> list, Criteria criteria) {
    Disjunction or = Restrictions.disjunction();
    if (list.size() > 1000) {
        while (list.size() > 1000) {
            List<?> subList = list.subList(0, 1000);
            or.add(Restrictions.in(propertyName, subList));
            list.subList(0, 1000).clear();
        }
    }
    or.add(Restrictions.in(propertyName, list));
    criteria.add(or);
}
 
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criteria.add(Restrictions.like("time","%" + "2018-11-13" + "%"));
criteria.add(Restrictions.sqlRestriction("time like '%2018-11-13%'"));
 
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//注意导入的包是import javax.persistence.criteria.CriteriaQuery;
try {
    session.beginTransaction();
    //1.创建CriteriaBuilder,用于创建查询
    CriteriaBuilder criteriaBuilder = session.getCriteriaBuilder();
    //2.创建CriteriaQuery,用于设置查询语句的信息
    CriteriaQuery<Student> criteriaQuery = criteriaBuilder.createQuery(Student.class);
    //3.定义查询的From子句中能出现的类型,也可以用root.get()获取具体的某个属性
    Root<Student> root = criteriaQuery.from(Student.class);
    //4.设置WHERE字句的条件，此处条件为score<= 98
    criteriaQuery.where(criteriaBuilder.lt(root.get("score"), 98));
    //5.设置排序标准与排序方式
    criteriaQuery.orderBy(criteriaBuilder.desc(root.get("score")));
    //6.创建Query对象并获取结果集list
    Query<Student> query = session.createQuery(criteriaQuery);
    List<Student> list = query.list();
    // List<Student> list = session.createQuery(criteriaQuery).getResultList();
    //7.遍历结果集
    list.forEach(System.out::println);
    session.getTransaction().commit();
} catch (Exception e) {
    e.printStackTrace();
    session.getTransaction().rollback();
}
 
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try {
    session.beginTransaction();
    //1.创建CriteriaBuilder
    CriteriaBuilder criteriaBuilder = session.getCriteriaBuilder();
    //2.创建CriteriaQuery
    CriteriaQuery<Country> criteriaQuery = criteriaBuilder.createQuery(Country.class);
    //3.设置distinct去重
    criteriaQuery.distinct(true);
    //4.获取root句柄
    Root<Country> root = criteriaQuery.from(Country.class);
    //5.设置fetch的连接对象以及连接类型，此处为迫切左外连接
    root.fetch("ministers", JoinType.LEFT);
    //6.设置where查询条件
    criteriaQuery.where(criteriaBuilder.equal(root.get("cid"), 1));
    //7.获取Query对象
    Query<Country> query = session.createQuery(criteriaQuery);
    //8.获取查询结构
    List<Country> list = query.list();
    // List<Student> list = session.createQuery(criteriaQuery).getResultList();
    for (Country country : list) {
	System.out.println(country);
	country.getMinisters().forEach(System.out::println);
    }
    session.getTransaction().commit();
} catch (Exception e) {
    e.printStackTrace();
    session.getTransaction().rollback();
}
 
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if (session != null) {
	session.flush();
	session.clear();
	session.close();
}
 
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/**
 * 验证缓存管理的方法evict
 * 执行完evict之后，将会将id为5的user对象从一级缓存中移除，再次访问的话将重新查询数据库
 * 该用例将发出2个select语句
 */
@Test
public void testEvict(){
	Session session = HibernateUtil.getSession();
	User user1 =  (User)session.get(User.class, 5);
	System.out.println(user1.getName());
	session.evict(user1);
	User user2 =  (User)session.get(User.class, 5);
	System.out.println(user2.getName());
	session.close();
}


/**
 * 验证缓存管理的方法clear
 * 执行clear方法之后，一级缓存中的对象全部被清除，再次查询，将从数据库中查询
 * 该用例将发出2个select语句
 */
@Test
public void testClear(){
	Session session = HibernateUtil.getSession();
	User user1 =  (User)session.get(User.class, 5);
	System.out.println(user1.getName());
	System.out.println("=======================");
	User user2 =  (User)session.get(User.class, 5);
	System.out.println(user2.getName());
	session.clear();


}
 
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ht.setFlushMode(HibernateTemplate.FLUSH_AUTO);
ht.getSessionFactory().getCurrentSession().setFlushMode(FlushMode.AUTO);
 
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// 原方式
getHibernateTemplate().save(user); 

// 更改后方式
getHibernateTemplate().execute(new HibernateCallback<User>() {
	@Override
	public User doInHibernate(Session session) throws HibernateException {
		session.save(user);
		return null;
	}
});

 
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