607. Sales Person

https://leetcode.com/articles/sales-person/

Method 1:

select distinct name from salesperson 

where sales_id  not in

(

select distinct sales_id  from orders  o 

left join company c on o.com_id = c.com_id 

where c.name =  'RED'

)

 

Method 2:

select distinct s.name name from salesperson s

left join orders o on o.sales_id  = s.sales_id 

left join company c on o.com_id = c.com_id 

where c.name <>  'RED' or c.name is null