Hi slange,

I think you're confusing a couple of possibilities.

The query above reports employees who have no "subordinates" - there are no employees that have their employeeid in the reportsto field.

The query that you are thinking of is almost exactly the opposite:

select *

from employees

left join employees as supervisors on employees.reportsto = supervisors.employeeid

where supervisors.employeeid Is Null

and employees.reportsto Is Not Null

It's actually slightly different because it also has an extra WHERE criterion - making sure that the employees returned actually have a reportsto value (for a supervisor that no longer exists, or never existed).

Does this help?