常用查询例子

创建数据庫表，并往里添加数据：

    article INT(4) UNSIGNED ZEROFILL DEFAULT '0000' NOT NULL,
    dealer  CHAR(20)                 DEFAULT ''     NOT NULL,
    price   DOUBLE(16,2)             DEFAULT '0.00' NOT NULL,
    PRIMARY KEY(article, dealer));
INSERT INTO shop VALUES
    (1,'A',3.45),(1,'B',3.99),(2,'A',10.99),(3,'B',1.45),

查询列特定列中的最大值

+---------+
| article |
+---------+
|       4 |
+---------+

也可以通过以下方式来达到同样的效果：

LEFT JOIN shop s2 ON s1.price < s2.price
WHERE s2.article IS NULL;
SELECT article, dealer, price
FROM shop
ORDER BY price DESC