Return the managers and Employees that reports to a manager

Question

Hello Everyone,
I need your help in the following query using connect by:
I have 2 tabels
Tabel_1
Department hierarchy
department_id parent_department_id has_manager
1 NULL X
2 1
3 1 X
4 2 X
5 4
tabel_2
emp_id department_id is_manager
1 1 X
2 1
3 1
4 2
5 2
6 4 X
7 4
8 4
9 3 X
10 5 X
now in my company the concept of direct employees is as follow:
my direct employees are: the employees in my department + only the manager in the department below me in the hierarchy.
if the department bellow me has no manager then also these employees in that department reports to me
then we check the lower department and so on untill we find a manger then this manager reports to me but his employees reports to him so they are not my direct employees
for the above example should be as follows
if i want to get the direct employees of emp_id= 1
then result is
2
3
4
5
6
9
Best regards
Ibrahim

Answer 1

Hi, Ibrahim,
Welcome to the forum!
Whenever you have a question, please post CREATE TABLE and INSERT statements for your sample data. Since this is your first post, I'll do it for you:
CREATE TABLE     department
(       department_id          NUMBER     PRIMARY KEY
,     parent_department_id     NUMBER
,     has_manager          VARCHAR2 (1)
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (1,            NULL,               'X');
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (2,            1,               NULL);
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (3,            1,               'X');
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (4,            2,               'X');
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (5,            4,               NULL);
CREATE TABLE     emp
(       emp_id          NUMBER     PRIMARY KEY
,     department_id     NUMBER
,     is_manager     VARCHAR2 (1)
INSERT INTO emp (emp_id, department_id, is_manager)
             VALUES (1,       1,                 'X');
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (2,       1,                 NULL);
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (3,       1,                 NULL);
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (4,       2,                 NULL);
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (5,       2,                 NULL);
INSERT INTO emp (emp_id, department_id, is_manager)
        VALUES (6,       4,                 'X');
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (7,       4,                 NULL);
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (8,       4,                 NULL);
INSERT INTO emp (emp_id, department_id, is_manager)
         VALUES (9,       3,                 'X');
INSERT INTO emp (emp_id, department_id, is_manager)
        VALUES (10,      5,                 'X');
913209 wrote:if the department bellow me has no manager then also these employees in that department reports to me
then we check the lower department and so on untill we find a manger then this manager reports to me but his employees reports to him so they are not my direct employeesWhat if a department directly below that has no manager? For example, if we add this to the sample data:
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (6,            2,               NULL);
INSERT INTO department (department_id, parent_department_id, has_manager)
                     VALUES (7,            6,               NULL);Would anyone working in departments 6 or 7 (as well as 1 or 2) be included? I assume so. If that's wrong, then you don't need CONNECT BY: a self-join would be enough.
Here's one way to do that:
WITH     my_departments     AS
     SELECT     department_id
     ,     LEVEL          AS lvl
     ,     SYS_CONNECT_BY_PATH (has_manager, '/')     AS manager_path
     FROM     department
     START WITH     department_id     = (
                                     SELECT  department_id
                               FROM    emp
                               WHERE   emp_id       = 1     -- Parameter
                               AND     is_manager  = 'X'
     CONNECT BY     parent_department_id     = PRIOR department_id
SELECT       e.emp_id
FROM       my_departments     d
JOIN       emp               e  ON   d.department_id  = e.department_id
WHERE       (    REGEXP_LIKE ( d.manager_path
                        , '^/X/*$'
       AND  e.emp_id        != 1          -- Parameter
OR       (    REGEXP_LIKE ( d.manager_path
                       , '^/X/*X$'
       AND  e.is_manager     = 'X'
ORDER BY  e.emp_id
;Another thing you should do in every thread is say which version of Oracle you're using. The query above will work in Oracle 10.1 and higher.
The tricky part of thsi query is that we really want to use this CONNECT BY clause:
...     CONNECT BY     parent_department_id     = PRIOR department_id
          AND     has_manager          IS NULLbut to go one more level, that is, find not only the nodes above, but also their immediate children. I can't think of a good way to do that which is not more complicated (and probably less efficient) than what I posted above.