leetcode 607 銷售員

select s.`name`
from salesperson s
left join
orders o
on s.sales_id=o.sales_id
left join 
company c
on o.com_id=c.com_id and c.name='RED'
group by s.sales_id
having count(c.`name`) = 0

select s.`name`
from salesperson s
where s.sales_id not in (
    select o.sales_id
    from
    orders o
    left join 
    company c
    on o.com_id=c.com_id
    where c.`name` = 'RED'
)