salesPerson.sql

-- +-------------+---------+
-- | Column Name | Type    |
-- +-------------+---------+
-- | com_id      | int     |
-- | name        | varchar |
-- | city        | varchar |
-- +-------------+---------+
-- Table: Orders
-- +-------------+------+
-- | Column Name | Type |
-- +-------------+------+
-- | order_id    | int  |
-- | order_date  | date |
-- | com_id      | int  |
-- | sales_id    | int  |
-- | amount      | int  |
-- +-------------+------+
-- Write a solution to find the names of all the salespersons who did not have any orders related to the company with the name "RED".
-- Return the result table in any order.
-- The result format is in the following example.
SELECT name
FROM SalesPerson
WHERE sales_id NOT IN (
    SELECT sales_id
    FROM Orders
    WHERE com_id = (
        SELECT com_id
        FROM Company
        WHERE name = 'red'
      )
  ) # OR As a join
SELECT DISTINCT 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
WHERE c.name IS NULL
  OR c.name != 'RED';