Select d.department_name "Department", l.city, e.emp_count
FROM
(Select department_name "Department" from Departments)d,
(Select city from Locations)l,
(Select ___________)e
order by d.department_name

SELECT tab1.Col1, tab1.col2, tab2.col1, tab2.col2, tab2,col3, tab3.col1
FROM tab1
JOIN tab2
ON tab1.colx = tab2.colx
JOIN tab3
ON tab2.coly =tab3.coly

SELECT Employees.Employee_ID, Employees.Department_ID, 
Departments.Department_ID, Departments.Department_Name, 
Departments. Location_ID, Locations.Location_ID, Locations.City
FROM Employees
JOIN Departments
ON Employees.Department_ID= Departments.Department_ID
JOIN Locations
ON Departments.Location_ID= Locations.Location_ID

select  department_name, city
FROM departments
natural join Locations;