sales_analysis2.sql

/*
Table: Product

+--------------+---------+
| Column Name  | Type    |
+--------------+---------+
| product_id   | int     |
| product_name | varchar |
| unit_price   | int     |
+--------------+---------+
product_id is the primary key of this table.
Each row of this table indicates the name and the price of each product.
Table: Sales

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| seller_id   | int     |
| product_id  | int     |
| buyer_id    | int     |
| sale_date   | date    |
| quantity    | int     |
| price       | int     |
+-------------+---------+
This table has no primary key, it can have repeated rows.
product_id is a foreign key to the Product table.
Each row of this table contains some information about one sale.
 

Write an SQL query that reports the buyers who have bought S8 but not iPhone. Note that S8 and iPhone are products present in the Product table.
*/

SELECT DISTINCT s.buyer_id
FROM Sales s JOIN Product p ON s.product_id = p.product_id
WHERE p.product_name='S8' AND s.buyer_id NOT IN (
    SELECT buyer_id 
    FROM Sales s JOIN Product p 
    ON s.product_id = p.product_id
    WHERE p.product_name='iPhone'
)