mysql从表中显示数据最大值和总和

Posted 2023-01-10

我有两张表，想显示SUM总和的MAX结果，按名称和月份分组，只显示每个月SUM总和结果的最大数据，按名称分组。

table t2
+-------+-------+-------+
| month | total | id_t3 |
+-------+-------+-------+
|   1   |  15   |   1   |
|   1   |  20   |   2   |
|   1   |  50   |   1   |
|   2   |  40   |   2   |
|   2   |  20   |   3   |
|   2   |  20   |   1   |
|   3   |  10   |   3   |
+-------+-------+-------+

table t3
+----+--------+
| id |  name  |
+----+--------+
| 1  |  brian |
| 2  |  jessi |
| 3  |  redy  |
+----+---------

i want result 
+-------+---------------+
| month | total |  name |
+-------+---------------+
|   1   |  65   | brian |
|   2   |  40   | jessi |
|   3   |  10   | redy  |
+-------+---------------+

这是我的查询SQL

select t2.month, MAX(total), t3.name
from (
select t2.month, SUM(t2.total)as total, t3.name
from t2, t3
where t2.idt3 = t3.id
group by t2.month, t3.name
)result
group by t2.month, t3.name
order by total DESC

答案

希望它能解决你的问题。group by 月份和名称

select t2.month, SUM(t2.total), t3.name
from t2
join t3 on t2.id_t3 = t3.id
group by t2.month, t3.name
order by t2.total desc

另一答案

如果你想要每个月最大的名字，使用窗口功能。

select month, name, total
from (select t2.month, t3.name, sum(t2.total) as total
             row_number() over (partition by t2.month order by sum(t2.total) desc) as seqnum
      from t2 join
           t3
           on t2.id_t3 = t3.id
      group by t2.month, t3.name
     ) t
where seqnum = 1
order by month;