关联数据查询

数据库中的表经常有业务关联关系。

UserVO.java 定义参数，添加getset方法和tostring方法

public class UserVO implements Serializable { private int empno; private String ename; private String dname;}

UserMapper.xml 定义sql语句

select e.empno, e.ename, d.dname from emp e left join dept d on e.deptno=d.deptno

UserMapper.java 定义抽象方法

List findUserDepartment();

测试方法

@Test public void testFindUserDepartment(){ UserMapper mapper = ctx.getBean("userMapper",UserMapper.class); List list = mapper.findUserDepartment(); list.forEach(u -> System.out.println(u)); }