SQL query to get the list of supervisor hierarchy. employee --> supervisor --> supervisor

问题

I have two tables Employee and Department this image shows the manager of every employee. I want to write a SQL query that gives me a list of all the supervisor (Manager, Manager of Manager..).

I just want a single column that displays a list of supervisor when given a particular employee.

E.g. If I give employee id = 202 then I should receive 200,130

 |supervisor |   
 +-----------+
 |   200     |      
 |   130     |

I have this query

WITH emp_dept as(
SELECT employee_id,manager_id 
FROM employee,department
WHERE employee.dept_id= department.dept_id
   ) 

 WITH recursive p as (
    select e1.employee_id, e1.manager_id
    from   emp_dept e1
    where    employee_id = 202

    union all

   select e2.employee_id , e2.manager_id
   from   p
   join   emp_dept e2 ON e2.employee_id = p.manager_id

)
select manager_id
from   p

I am not able to use it. I am using pgadmin4.

If anyone could help me with this query I would greatly appreciate it

回答1:

I think you can use "hierarchical queries" for Oracle and try this:

select manager_id supervisor 
from employee
start with employee_id = 202
connect by nocycle employee_id = prior manager_id;

回答2:

This is the solution to my question

  with recursive p as (
WITH emp_dept as(
SELECT employee_id,manager_id 
FROM employee,department
WHERE employee.dept_id= department.dept_id
) 

select e1.employee_id, e1.manager_id
from   emp_dept e1
where  e1.employee_id = 202

union 

select e2.employee_id , e2.manager_id
from   p
join   emp_dept e2 ON e2.employee_id = p.manager_id

)
select manager_id
  from   p

来源：https://stackoverflow.com/questions/49962130/sql-query-to-get-the-list-of-supervisor-hierarchy-employee-supervisor-s

标签

sql

postgresql

hierarchical-data

recursive-query