如何在不使用全部工会的情况下使用sql递归？

Question

我对sql递归理论有疑问。定义：如果公用表表达式在其定义中使用自己，则称为递归。FedEmp(name, salary, manager)

找到所有在胡佛管理下并且薪水超过100000的员工

with agents(name, salary) as
    ((select name, salary                   --initial query
      from FedEmp 
      where manager = ‘Hoover’)
    union all
     (select f.name, f.salary               --recursive query
      from agents as a, FedEmp As f
      where f.manager = a.name))
select name from agents;                    --final query