mysql子查询并具有子查询的最大值答案

【问题标题】：mysql subquery and having max value of subquerymysql子查询并具有子查询的最大值
【发布时间】：2012-05-05 09:29:44
【问题描述】：

SELECT plaka, party_id, sum(inf) i 
  FROM party_sehir
 GROUP BY party_id, plaka

这是我的子查询，结果是：

plaka   party_id   i 
34      1          42
34      2          9
35      1          11
35      2          26

从这些结果中，我想获得每个 plaka 和行 party_id 的最大 i，如下所示：

plaka  party_id    i 
34     1           42
35     2           26

我的意思是每个plaka 的最大值。我也试过了：

SELECT * 
  FROM ( SELECT plaka, party_id, sum(inf) i 
           FROM party_sehir
          GROUP BY party_id, plaka ) t1 
 GROUP BY plaka  
HAVING i >= max(i)

没用；有人可以帮忙吗？

谢谢

【问题讨论】：

标签： mysql subquery max having

【解决方案1】：

它需要更长的查询，比如

select plaka,party_id, i 
from
(SELECT plaka,party_id, sum(inf) i FROM party_sehir
 GROUP BY  party_id, plaka) sum_group
where (i,plaka) in (
SELECT max(i), plaka
 FROM (SELECT plaka,party_id, sum(inf) i FROM party_sehir
 GROUP BY  party_id, plaka) t1 group by plaka )

【讨论】：

【解决方案2】：

请尝试 group by 以获得您的解决方案

SELECT plaka ,party_id   , max( `i` ) FROM `party_sehir` GROUP BY `plaka`

或

SELECT * FROM `party_sehir` AS s1 WHERE s1.i = (SELECT max( `i` ) FROM party_sehir AS  
   s2  WHERE s1.plaka = s2.plaka ) GROUP BY `plaka`

【讨论】：