The Rows Holding the Group-wise Maximum of a Certain Column .

SELECT article, dealer, price 

FROM shop s1
WHERE price=(SELECT MAX(s2.price)
                        FROM shop s2 WHERE s1.article = s2.article)
ORDER BY article;The preceding example uses a correlated subquery, which can be inefficient . Other possibilities for solving the problem are to use an uncorrelated subquery in the FROM clause, a LEFT JOIN, or a common table expression with a window function.

Uncorrelated subquery:
SELECT s1.article, dealer, s1.price FROM shop s1 JOIN ( SELECT article, MAX(price) AS price FROM shop GROUP BY article) AS s2 ON s1.article = s2.article AND s1.price = s2.price ORDER BY article;
LEFT JOIN
SELECT s1.article, s1.dealer, s1.price FROM shop s1 LEFT JOIN shop s2 ON s1.article = s2.article AND s1.price < s2.price WHERE s2.article IS NULL ORDER BY s1.article;

The LEFT JOIN works on the basis that when s1.price is at its maximum value, there is no s2.price with a greater value and thus the corresponding s2.articlevalue is NULL. 

Common table expression with window fonction

WITH s1 AS
( SELECT article, dealer, price,
RANK() OVER (PARTITION BY article
ORDER BY price DESC
) AS `Rank`
FROM shop ) SELECT article, dealer, price FROM s1 WHERE `Rank` = 1 ORDER BY article;