经典hql语句

1.hql更新 String hql = "update PhUser set realName=?"; int row=this.getSession().createQuery(hql).setString(0, "小李想").executeUpdate(); PhUser 类名 2.hql删除 String hql = "delete PhUser a where a.userId=2"; int row=this.getSession().createQuery(hql).executeUpdate(); 还有个这种的格式: final String hql = "delete PhRoleFunction as a where a.roleId = " + roleId; this.getHibernateTemplate().execute(new HibernateCallback() { public Object doInHibernate(Session session) throws HibernateException, SQLException { return session.createQuery(hql).executeUpdate(); } });更新也可以写成这样的格式 3.hql单表查询 String hql = "from PhUser a where a.userId=" + userId; List list = this.getHibernateTemplate().find(hql); 4.hql多表查询 (1)String hql = "select new map(a.CUId as CUId,a.unitName as unitName,b.CUFId as CUFId,b.UFName as UFName) from PhCorrelativeUnit a,PhCorrelativeUnitFunction b where a.CUId=b.CUId"; List list = this.getHibernateTemplate().find(hql); 多个表的字段放到map中,map的键值就是as后面的别名,如果没有as就是字段名 (2) String hql = "select new com.phantom.appeal.action.bean.DealPaper(a.id as id,a.billId as billId,a.state as     state,a.creator as creator,a.createtime as createtime ,b.eventContent as eventContent ,c.realName as     realName,b.billCode as billCode,b.citName as citName ) from PhDealBill a,PhAcceptBill b,PhUser c where    a.departmentId="+ billid+ " and a.state=0 and a.billId=b.billId and a.creator =c.userId order by a.billId"; return this.getHibernateTemplate().find(hql); 另外就是写一个类,对应你要查询的字段,这里的类名是new com.phantom.appeal.action.bean.DealPaper,里面对应查询的字段名 5.得到记录数 String hql = "select count(*) from PhUser"; List list = this.getHibernateTemplate().find(hql); return ((Long) list.get(0)).intValue();     五种检索方式的使用场合和特点： HQL ： 是面向对象的查询语言，同SQL有些相似是Hib中最常用的方式。        查询设定各种查询条件。        支持投影查询，检索出对象的部分属性。        支持分页查询，允许使用having和group by        提供内制的聚集函数，sum()，min()，max()        能调用用户的自定义SQL        支持子查询，嵌入式查询        支持动态绑定参数 建议使用Query接口替换session的find方法。    Query Q = session.createQuery("from customer as c where c.name = :customerName" + "and c.age = :customerAge");    query.setString ("customerName" , "tom");    query.setInteger("customerAge" , "21");    list result = query.list(); QBC : QBCAPI提供了另一种方式，主要是Criteria接口、Criterion接口和Expression类    Criteria criteria = session.createCriteria(customer.class);    Criterion criterion1 = Expression.like("name","t%");    Criterion criterion2 = Expression.eq("age",new Integer(21));    Critera = criteria.add(criterion1) ;    Critera = criteria.add(criterion2) ;    list result = criteria.list();    或是： list result = session.createCriteria(Customer.class).add(Expression.eq("this.name","tom")).list(); SQL : 采用HQL和QBC检索时，Hib生成SQL语句适用所有数据库。    Query query = session.createSQLQuery("select {c.*} from customers c where c.name like : customername " + "and c.age = :customerage","c",customer.calss);    query.setString("customername","tom");    query.setInteger("customerage","21");    list result = query.list(); /////////////多态查询    HQL ：session.createQuery("from employee");    QBC ：session.createCriteria(employee.class);    HQL : session.createQuery("from hourlyEmployee");    QBC : session.createCriteria(hourlyEmployee.class);    下面的HQL查询语句将检索出所有的持久化对象：    from java.lang.Object ;    from java.io.serializable ; ////////////查询的排序    1'查询结果按照客户姓名升序排列：    HQL ：         Query query = session.createQuery ("from customer c order by c.name");    QBC ：         Criteria criteria = session.createCriteria(customer.class);         criteria.addOrder(order.asc("name"));    HQL :         Query query = session.createQuery ("from customer c order by c.name asc , c.age desc");    QBC :         Criteria criteria = session.createCriteria(customer.class);         criteria.addOrder(order.asc ("name"));         criteria.addOrder(order.desc("age"));         import net.sf.hibernate.pression.Order         import mypack.Order         ...........         Criteria criteria = session.createCritria (mypack.Order.class);         criteria.addOrder(net.sf.hibernate.Order.asc("name")); ///////////HQL语句的参数绑定Query接口提供了绑定各种Hib映射类型的方法。         setBinary()         setString()         setBoolean()         setByte()         setCalendar()         setCharacter()         setDate()         setDouble()         setText()         setTime()         setTimestamp()         setEntity()//把参数与一个持久化类的事例绑定lsit result = session.createQuery("from order o where o.customer =            :customer").setEntity("customer" , customer).list ;         setParameter()//绑定任意类型的参数         setProperties()//把命名参数与一个对象的属性值绑定 Query query = session.createQuery("from customer c where c.name =:     name " + "and c.age =:age" );         Query.setProperties(customer); 过滤查询结果中的重复元素      使用Set集合来去除重复元素；或是使用distinct元素      Iterator iterator = session.createQuery("select distinct c.name from customer ").list().iterator();      while(iterator.hasnext()){            String name = (String) it.next() ;      } ///////////使用聚集函数 count(); 记录的条数 min();   求最小值 max();   求最大值 avg();   求平均值 sum();   求和 1'查询customer中的所有记录条数    integer i = (Integer) session.createQuery("select count(*) from customer").uniqueResult(); 2'查询customer中的所有客户的平均年龄    integer i = (Integer) session.createQuery("select avg(c.age) from customer c ").uniqueResult(); 3'查询customer中的客户年龄的最大值、最小值    object [] i = (Integer) session.createQuery("select max(c.age),min(c.age) from customer c ").uniqueResult();    Integer Maxage = (Integer) i [0];    Integer Minage = (Integer) i [1]; 4'统计customer中的客户的名称数目，忽略重复的姓名    Integer cout = (Integer) session.createQuery("select count(distinct c.name) from customer c").uniqueResult(); ////////////使用分组查询 1'按姓名分组，统计customer中的相同姓名的记录数目    Iterator iterator = (Integer) session.createQuery("select c.name ,count(c) from customer c group by c.name").list.iterator();    while(iterator.hasnext()){          object[] p = (objcet[])iterator.next();          String name = p[0];          Integer cout = p[1];    } 2'按客户分组，统计每个客户的订单数量    Iterator iterator = session.crateQuery("select c.id ,c.name , count(o) from customer c join c.order o group by c.id ").list().iterator;    while(iterator.hasnext()){          object[] p = (objcet[])iterator.next();          Integer id = p[0]          String name = p[1];          Integer cout = p[2];    } 3'统计每个客户的订单总价    Iterator iterator = session.crateQuery("select c.id ,c.name,sum(o.price) from customer c join c.order o group by c.id").list.iterator();    while(iterator.hasnext()){          object[] p = (objcet[])iterator.next();          Integer id = p[0]          String name = p[1];