按组排序"汇总"

Question

我发现group by使用的"with rollup"选项非常有用.但它不符合"order by"条款.有没有办法按我想要的方式订购以及计算小计？

CREATE TABLE `mygroup` (
  `id` int(11) default NULL,
  `country` varchar(100) default NULL
) ENGINE=MyISAM ;

INSERT INTO `mygroup` VALUES (1,'India'),(5,'India'),(8,'India'),(18,'China'),(28,'China'),(28,'China');

mysql>select country, sum(id) from mygroup group by country with rollup; 
+---------+---------+
| country | sum(id) |
+---------+---------+
| China   |      74 | 
| India   |      14 | 
| NULL    |      88 | 
+---------+---------+
3 rows in set (0.00 sec)

mysql>select country, sum(id) as cnt from mygroup group by country order by cnt ;
+---------+------+
| country | cnt  |
+---------+------+
| India   |   14 | 
| China   |   74 | 
+---------+------+
2 rows in set (0.00 sec)

mysql>select country, sum(id) as cnt from mygroup group by country with rollup order by cnt;
ERROR 1221 (HY000): Incorrect usage of CUBE/ROLLUP and ORDER BY

Expected Result:
+---------+------+
| country | cnt  |
+---------+------+
| India   |   14 | 
| China   |   74 | 
| NULL    |   88 | 
+---------+---------+
3 rows in set (0.00 sec)

Answer 1

尝试使用临时表

 SELECT * 
 FROM 
 (
     SELECT country, sum(id) as cnt 
     FROM mygroup GROUP BY country WITH rollup
 ) t 
 ORDER BY cnt;

本文可以帮助您链接文本

Answer 2

您是否尝试过将订单放入分组中？

SELECT country, SUM(id) 
    FROM mygroup 
GROUP BY country DESC WITH ROLLUP;

应该返回:

+---------+---------+
| country | SUM(id) |
+---------+---------+
| India   |      14 |
| China   |      74 |
| NULL    |      88 |
+---------+---------+

http://dev.mysql.com/doc/refman/5.0/en/group-by-modifiers.html