Criteria查询.doc

Hibernate的三种查询方式1.HQL (Hibernate Query Lanuage) 语句，这是类似SQL语句的一种对象化查询语句.2.使用Criteria对象，进行按条件查询(Query by Criteria，简称QBC)和按示例查询(Query by Example 简称QBE).3.生成原生的sql(Native SQL)语句.Criteria的基本使用Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. Listlist=criteria.list();4. mit();查询Testbook 中所有的数据，然后返回Criteria 接口的核心方法add() 增加一个代表查询条件的Criterion对象addOrder() 增加一个代表排序的Criterion对象createAlias() 创建关联查询，为所关联的持久化类建立别名createCriteria() 在相互关联的持久化类之间建立条件约束setFirstResult() 设定要获取的第一条记录的位置setMaxResults() 设定要获取的记录的最大数量list() 获取满足查询条件的记录的集合uniqueResult() 获取满足查询条件的唯一记录对查询结果进行排序Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class).add(3. Restrictions.like(name,任%).add(Restrictions.between(id,1000,1010);4. criteria.addOrder(Order.desc(id).addOrder(Order.asc(createdTime);5. Listlist=criteria.list();6. mit();实现分页显示数据Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class).add(3. Restrictions.like(name,任%);4. criteria.addOrder(Order.desc(id);5. criteria.setMaxResults(30);6. criteria.setFirstResult(10);/setFirstResult()从0开始计数7. Listlist=criteria.list();8. mit();只查询一条记录Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class).add(3. Restrictions.like(name,任%);4. criteria.addOrder(Order.desc(id);5. criteria.setMaxResults(1);6. Testbooktb=(Testbook)criteria.uniqueResult();7. mit();Restrictions类条件或方式组合查询条件Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. Criterioncriterion1=Restrictions.or(Restrictions.like(name,任%),4. Restrictions.between(id,1000,1010);5. criteria.add(criterion1);6. Listlist=criteria.list();7. mit();使用原生SQL语句设定查询条件Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. criteria.add(Restrictions.sqlRestriction(=?,Narcissus,Hibernate.STRING);4. Listlist=criteria.list();5. mit()统计函数查询Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. criteria.setProjection(Projections.max(price);4. DoublemaxValue=(Double)criteria.uniqueResult();5. mit();6. System.out.println(maxValue);统计函数组合查询条件Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. criteria.setProjection(Projections.max(price);4. DoublemaxValue=(Double)criteria.uniqueResult();5. mit();6. System.out.println(maxValue);获取多个统计函数的值Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. ProjectionListproList=PjectionList();4. proList.add(Projections.max(price);5. proList.add(Projections.min(price);6. proList.add(Projections.avg(price);7. proList.add(Projections.sum(price);8. proList.add(Projections.count(price);9. proList.add(Projections.countDistinct(price);10. proList.add(Projections.rowCount();11. criteria.setProjection(proList);12. Objectvalues=(Object)criteria.uniqueResult();13. mit();分组查询Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. criteria.setProjection(Projections.groupProperty(price);4. Listlist=criteria.list();5. mit();分组统计Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. ProjectionListproList=PjectionList();4. proList.add(Projections.rowCount();/商品的个数5. proList.add(Projections.sum(price);6. proList.add(Projections.groupProperty(name);7. criteria.setProjection(proList);8. Listlist=criteria.list();9. mit();投影查询在一个表中有很多个字段，投影查询只是查询某一个或多个字段，也称局部查询Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. criteria.setProjection(Property.forName(price);4. criteria.add(Restrictions.gt(price,newDouble(40.0)5. Listlist=criteria.list();6. mit();使用Property类的forName()方法实现分组统计Java代码1. Transactiontx=session.beginTransaction();2. Criteriacriteria=session.createCriteria(Testbook.class);3. ProjectionListproList=PjectionList();4. proList.add(Projections.forName(price).max();5. proList.add(Projections.forName(price).min();6. proList.add(Projections.forName(price).avg();7. proList.add(Projections.forName(category.id).group().as(c);8. criteria.setProjection(proList);9. criteria.addOrder(Order.desc(c);10. Listlist=criteria.list();11. mit();使用DetachedCriteria对象实现离线查询Java代码1. /在表现层，构造DetachedCriteria对象，保存用户动态的查询条件2. DetachedCriteriadetchedCriteria=DetachedCriteria.forClass(Testbook.class);3. detchedCriteria.add(Restrictions.like(name,任%).add(Restrictions.between(id,newInteger(1),newInteger(10);4. detchedCriteria.addOrder(Order.desc(id);5. 6. /在业务逻辑层，DetachedCriteria对象与当前的Session对象进行绑定，获取查询结果7. Sessionsession=HibernateSessionFactoryUtil.getSessionFactory().getCurrentSession();8. Transactiontx=detchedCriteria.getExecutableCriteria(session);9. Listlist=criteria.list();10. mit();根据示例对象进行查询先定义一个模板然后把这个模板的样式传进去，查询，例如这里定义的Testbook中的名字为Narcissus的字段，进行查询，条件可以为一个也可以为多个，对应的就是where中的条件Java代码1. Testbooktb=newTestbook();2. tb.setName(Narc