Hibernate查询.doc

Hibernate查询方式一、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.二、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，然后返回三、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四、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();五、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();六、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();七、Restrictions类HQL运算符QBC运算符含义=Restrictions.eq()等于equalRestrictions.ne()不等于not equalRestrictions.gt()大于greater than=Restrictions.ge()大于等于greater than or equalRestrictions.lt()小于less than=Restrictions.le()小于等于less than or equalis nullRestrictions.isnull()等于空值is not nullRestrictions.isNotNull()非空值likeRestrictions.like()字符串模式匹配andRestrictions.and()逻辑与andRestrictions.conjunction()逻辑与orRestrictions.or()逻辑或orRestrictions.disjunction()逻辑或notRestrictions.not()逻辑非in(列表)Restrictions.in()等于列表中的某一个值not in(列表)Restrictions.not(Restrictions.in()不等于列表中任意一个值between x and yRestrictions.between()闭区间xy中的任意值not between x and yRestrictions.not(Restrictions.between()小于值X或者大于值y八、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();九、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()十、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);十一、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);十二、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();十三、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();十四、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();十五、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();十六、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();十七、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.