select s.name from salesperson s where s.sales_id not in ( select distinct o.sales_id from orders o, company c where c.com_id = o.com_id and c.name ='RED')
I firstly want to join salesperson to the subquery where c.name != 'RED'. but it turns out not working. Any one know why?
All comments appreciate.
@luckymyli same issue, don't know why