hibernate之13.hql(一)

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查询所有数据：

@Testpublic void queryAllTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="from Student";Query query=session.createQuery(hql);List<Student> list=query.list();for(Student student: list){System.out.println(student);}}finally{session.close();}}

基于参数查询:

@Testpublic void queryWithParamTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="from Student where studentId=?";Query query=session.createQuery(hql);query.setInteger(0, 83);List<Student> list=query.list();for(Student student: list){System.out.println(student);}}finally{session.close();}}

基于命令参数查询

@Testpublic void queryWithEqualsNamedParamTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="from Student where studentId=:studentId";Query query=session.createQuery(hql);query.setInteger("studentId", 83);List<Student> list=query.list();for(Student student: list){System.out.println(student);}}finally{session.close();}}

Like:

@Testpublic void queryWithLikeTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="from Student where studentName like ?";Query query=session.createQuery(hql);query.setString(0, "%王%");List<Student> list=query.list();for(Student student: list){System.out.println(student);}}finally{session.close();}}

in:

@Testpublic void queryWithInTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="from Student where studentId in (:stuIds)";Query query=session.createQuery(hql);query.setParameterList("stuIds", new Integer[]{63,83});List<Student> list=query.list();for(Student student: list){System.out.println(student);}}finally{session.close();}}

查询部份字段:

@Testpublic void queryColumnsTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="select studentId,studentName from Student where studentName like ?";Query query=session.createQuery(hql);query.setString(0, "%王%");List<Object[]> list=query.list();for(Object[] objs: list){System.out.println(objs[0]+" "+objs[1]);}}finally{session.close();}}

查询单个字段:

@Testpublic void querySingleColumnTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="select studentName from Student where studentName like ?";Query query=session.createQuery(hql);query.setString(0, "%王%");List<String> list=query.list();for(String name: list){System.out.println(name);}}finally{session.close();}}

查询统计:

@Testpublic void queryCountTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="select count(*) from Student where studentName like ?";Query query=session.createQuery(hql);query.setString(0, "%王%");List<Long> list=query.list();for(Long cnt: list){System.out.println(cnt);}}finally{session.close();}}

单个结果集

@Testpublic void queryUniqueResultTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="select stu from Student stu where stu.studentId=?";Query query=session.createQuery(hql);query.setInteger(0, 83);Student stu=(Student)query.uniqueResult();System.out.println(stu);}finally{session.close();}}

分页查询:

@Testpublic void queryPagerTest(){Session session=null;try{session=HibernateUtil.openSession();String hql="select stu from Student stu where studentName like ?";Query query=session.createQuery(hql);//从第几条记录开始query.setFirstResult(1);//每页大小query.setMaxResults(20);query.setString(0, "%王%");List<Student> list=query.list();for(Student stu: list){System.out.println(stu);}}finally{session.close();}}

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