Task: Find the number, dealer, and price of the most expensive article.任务:找到最昂贵物品的编号、经销商和价格。
This is easily done with a subquery:这可以通过子查询轻松完成:
SELECT article, dealer, price FROM shop WHERE price=(SELECT MAX(price) FROM shop); +---------+--------+-------+ | article | dealer | price | +---------+--------+-------+ | 0004 | D | 19.95 | +---------+--------+-------+
Other solutions are to use a 其他解决方案是使用LEFT JOIN
or to sort all rows descending by price and get only the first row using the MySQL-specific LIMIT
clause:LEFT JOIN
或按价格降序排列所有行,并使用MySQL特定的LIMIT
子句仅获取第一行:
SELECT s1.article, s1.dealer, s1.price FROM shop s1 LEFT JOIN shop s2 ON s1.price < s2.price WHERE s2.article IS NULL; SELECT article, dealer, price FROM shop ORDER BY price DESC LIMIT 1;
If there were several most expensive articles, each with a price of 19.95, the 如果有几个最昂贵的物品,每个物品的价格为19.95,LIMIT
solution would show only one of them.LIMIT
解决方案将只显示其中一个。