HQL条件查询

向右看齐 2022-05-24 11:22 227阅读 0赞

##### 【例】雇员信息 #####

![20180526100539155][]

##### 比较运算：查询姓名为“李树生”的雇员信息 #####

session=HibernateSessionFactory.getSession();
    			String hql="from Employee e where e.emp_name=?";
    			Query query=session.createQuery(hql);
    			query.setParameter(0, "李树生");
    			List<Employee>list=query.list();
    			for(Employee emp:list){
    				System.out.println(emp.getEmp_id()+"  "+emp.getEmp_name()+"  "+emp.getEmp_sex()+  
                            "  "+emp.getEmp_birth()+"  "+emp.getEmp_job()+"  "+emp.getEmp_salary());  
    			}

运行结果：

##### ![20180526100817352][]范围运算：查询薪水在6000到8000之间雇员信息 #####

session=HibernateSessionFactory.getSession();
    			String hql="from Employee e where e.emp_salary between ? and ?";
    			Query query=session.createQuery(hql);
    			query.setDouble(0, 6000);
    			query.setDouble(1, 8000);
    			List<Employee>list=query.list();
    			for(Employee emp:list){
    				System.out.println(emp.getEmp_id()+"  "+emp.getEmp_name()+"  "+emp.getEmp_sex()+  
                            "  "+emp.getEmp_birth()+"  "+emp.getEmp_job()+"  "+emp.getEmp_salary());  
    			}

运行结果：

![2018052610200877][]

##### 模糊查询：查询所有姓李的雇员信息 #####

session=HibernateSessionFactory.getSession();
    			String hql="from Employee e where e.emp_name like ?";
    			Query query=session.createQuery(hql);
    			query.setString(0, "%李%");
    			List<Employee>list=query.list();
    			for(Employee emp:list){
    				System.out.println(emp.getEmp_name());  
    			}

运行结果：

![20180526105414948][]

##### 分组查询：根据职位进行分组 #####

session=HibernateSessionFactory.getSession();
    			String hql="from Employee e group by e.emp_job";
    			Query query=session.createQuery(hql);
    			List<Employee>list=query.list();
    			for(Employee emp:list){
    				System.out.println(emp.getEmp_id()+" " +emp.getEmp_name()+" "+emp.getEmp_sex()
    				+" "+emp.getEmp_job());  
    			}

运行结果：

![20180526110201720][]

##### 子查询：查询所有职位为销售员的雇员信息 #####

session=HibernateSessionFactory.getSession();
    			String hql="from Employee e where e.emp_job in(select e.emp_job from Employee e where e.emp_job='销售员' )";
    			Query query=session.createQuery(hql);
    			List<Employee>list=query.list();
    			for(Employee emp:list){
    				System.out.println(emp.getEmp_id()+" " +emp.getEmp_name()+" "+emp.getEmp_sex()
    				+" "+emp.getEmp_job());  
    			}

运行结果：

![20180526110659614][]

[20180526100539155]: /images/20220524/5d48bb1477bb413ebdcc8e84818bd328.png
[20180526100817352]: /images/20220524/11345cba207c4b3ca7c1bbfff0d4df74.png
[2018052610200877]: /images/20220524/4644be9ccf0a4f078dcc487a5b5863e2.png
[20180526105414948]: /images/20220524/95a9108a6ce143069bce8bde950917b6.png
[20180526110201720]: /images/20220524/8efcfa28a7ee4612a31bce9acf8b0637.png
[20180526110659614]: /images/20220524/9dbbf91bbc2a47f583a89f1ebdc02bf4.png