Oracle SQL Query: Employees Managers & Supervisors

[Naeem]

Hello,

I have written the below queries, can somebody tell me if they are correct. manager_id in Employee Table - supervisor ; manager_id in departments table - manager.

names and department names of managers who do not supervise any employee.

select e.first_name|| ' ' ||e.last_name employee_name,d.department_name
from employees e join departments d
on e.employee_id =d.manager_id
where e.employee_id not in(select manager_id from employees where manager_id is not null)

supervisors but not managers

select e.first_name|| ' ' ||e.last_name employee_name
from employees e where e.employee_id in(select manager_id from employees where manager_id is not null)
and e.employee_id in (select manager_id from departments where manager_id is not null);

Employees who are managers and supervisors.

select e.first_name|| ' ' ||e.last_name employee_name
from employees e where e.employee_id in(select manager_id from employees where manager_id is not null)
and e.employee_id in (select manager_id from departments where manager_id is not null);

Any feedback much appreciated.

 

[Valkarie]

Yes, the queries are correct. However, you may want to consider adding an alias for the employee name column. For example: select e.first_name|| ' ' ||e.last_name AS employee_name,d.department_namefrom employees e join departments don e.employee_id =d.manager_idwhere e.employee_id not in(select manager_id from employees where manager_id is not null)