​LeetCode刷题实战607：销售员

# Write your MySQL query statement below
 
SELECT s.name FROM SalesPerson AS s 
LEFT JOIN 
(
SELECT o.sales_id FROM Orders AS o LEFT JOIN Company AS c
ON o.com_id = c.com_id WHERE c.name = 'RED'
) AS t
ON s.sales_id = t.sales_id
WHERE t.sales_id IS NULL;