Question

oracle的递归能全部显示上下级关系吗

Answer 1

可以的
--层次查询，自底到顶
select t.employee_id,t.last_name,t.job_id,t.manager_id,level from employees t
start with t.employee_id=101
connect by prior t.manager_id=t.employee_id;

select t.empno,t.ename,t.job,t.mgr,level from emp t
start with t.empno=7788
connect by prior t.mgr=t.empno;

--层次查询，自顶到底
select t.employee_id,t.last_name,t.job_id,t.manager_id,level from employees t
start with t.employee_id=101
connect by prior t.employee_id=t.manager_id;

select t.empno,t.ename,t.job,t.mgr,level from emp t
start with t.empno=7788
connect by prior t.empno=t.mgr;

Answer 2

当然可以的