Hibernate--使用setProperties()方法动态生成

女爷i 2024-02-17 17:01 10阅读 0赞

在Hibernate中可以使用setProperties()方法，将命名参数与一个对象的属性值绑定在一起!

**查询工资>1000,职位是CLERK,雇佣日期从1980-10-1 到1983-10-1？**

\--sql语句如下：

select \* from emp where sal>1000 and job='CLERK' and hiredate>to\_date('1980-12-01','yyyy-MM-dd')  
and hiredate<to\_date('1983-01-1','yyyy-MM-dd')

1）封装对象（有4个属性）

/**
     * 封装条件
     * @author Administrator
     *
     */
    public class EmpCondition {
    	private String jobs;
    	private Double salary;
    	private Date hiredateStart;
    	private Date hiredateEnd;
    
    	public String getJobs() {
    		return jobs;
    	}
    
    	public void setJobs(String jobs) {
    		this.jobs = jobs;
    	}
    
    	public Double getSalary() {
    		return salary;
    	}
    
    	public void setSalary(Double salary) {
    		this.salary = salary;
    	}
    
    	public Date getHiredateStart() {
    		return hiredateStart;
    	}
    
    	public void setHiredateStart(Date hiredateStart) {
    		this.hiredateStart = hiredateStart;
    	}
    
    	public Date getHiredateEnd() {
    		return hiredateEnd;
    	}
    
    	public void setHiredateEnd(Date hiredateEnd) {
    		this.hiredateEnd = hiredateEnd;
    	}
    
    }

2)使用这个实体类

@Test
    	public void list6() {
    		// 1.获得会话对象
    		Session session = HibernateUtil.currentSession();
    
    		// 条件对象
    		EmpCondition condition = new EmpCondition();
    		condition.setJobs("CLERK");
    		condition.setSalary(1000.0);
    		condition.setHiredateStart(Tool.strOrDate("1980-12-01", "yyyy-MM-dd"));
    		condition.setHiredateEnd(Tool.strOrDate("1983-01-01", "yyyy-MM-dd"));
    
    		// 2sql
    		StringBuffer hql = new StringBuffer("from Emp e where 1=1");
    
    		// 判断当前对象是否为空
    		if (null != condition.getSalary()) {
    			hql.append(" and e.sal>:salary");
    		}
    		if (null != condition.getJobs()) {
    			hql.append(" and e.job=:jobs");
    		}
    		if (null != condition.getHiredateStart()) {
    			hql.append(" and e.hiredate>:hiredateStart");
    		}
    		if (null != condition.getHiredateEnd()) {
    			hql.append(" and e.hiredate<:hiredateEnd");
    		}
    
    		// 3.获得Query对象
    		Query query = session.createQuery(hql.toString());
    
    		// 动态生成/
    		query.setProperties(condition);
    		// //
    
    		// 4.获得list对象
    		List<Emp> list = query.list();
    
    		// 5.遍历数据
    		for (Emp emp : list) {
    			System.out.println(emp.getEmpno() + "\t" + emp.getEname() + "\t"
    					+ emp.getJob() + "\t" + emp.getSal() + "\t"
    					+ emp.getHiredate());
    		}
    
    		// 6.将会话关闭
    		session.close();
    
    	}

3)可以根据具体的条件（可以是1个或2个或3个或4个等等）来查询数据。