MYSQL查询语句效率问题
任务:找出最贵物品的编号、销售商和价格。
表如下:
+---------+--------+-------+
| article | dealer | price |
+---------+--------+-------+
| 0001 | A | 3.45 |
| 0001 | B | 3.99 |
| 0002 | A | 10.99 |
| 0003 | B | 1.45 |
| 0003 | C | 1.69 |
| 0003 | D | 1.25 |
| 0004 | D | 19.95 |
+---------+--------+-------+
比较以下几条sql语句执行效率:
1.SELECT article, dealer, price
FROM shop
WHERE price=(SELECT MAX(price) FROM shop);
2. select s1.article,s1.dealer,s1.price
from shop s1,(select max(price) price from shop) s2
where s1.price = s2.price;
3.SELECT article, dealer, price
FROM shop
ORDER BY price DESC
LIMIT 1;
以上三条那条执行效率高?
如果您有更好的请写下来,谢谢各位!!