SQL 例子

1:  分组，再选出每组最大值：
  SELECT article, MAX(price) AS price
     FROM shop
     GROUP BY article
     ORDER BY article;
   +---------+-------+
    | article | price | +
   ---------+-------+
   | 0001 | 3.99 |
   | 0002 | 10.99 |
    | 0003 | 1.69 |
     | 0004 | 19.95 |
     +---------+-------+