Join a table to itself

Question

this is one on my database tables template.

Id int PK
Title nvarchar(10) unique
ParentId int 

This is my question.Is there a problem if i creat

Answer 1

Its called Self Join and it can be added to a table as in following example

select e1.emp_name 'manager',e2.emp_name 'employee'
from employees e1 join employees e2
on e1.emp_id=e2.emp_manager_id