On the web page, you have:
"we want to first select all of the values for ManagerID and then associate them with a name. We can do that with the following set of queries
SELECT EmployeeName AS Employee
WHERE EmployeeID IN (SELECT DISTINCT ManagerID FROM Employees)"
Would it be the same if I were to write it like this without using a subquery?
select distinct managerID, employeename
where managerid <> null;