sql - Query returns cartesian product (Northwind) -

i using northwind database in oracle.

task : fetch no. of employees working in each region.

result: (regionname, no. of employees)

i trying query return cartesian product

select r.regiondescription, count(e.employeeid) employees e,      employeeterritories et,      territories t,      region r  r.regionid = t.regionid   , et.territoryid = t.territoryid   , e.employeeid = et.employeeid group r.regiondescription; 

question: wrong query?

the thing can think of, 1 of table multiplying results, , should use count(distinct) instead:

select r.regiondescription, count(distinct e.employeeid) employees e,      employeeterritories et,      territories t,      region r  r.regionid = t.regionid   , et.territoryid = t.territoryid   , e.employeeid = et.employeeid group r.regiondescription;