选择按两列分组的最大值

Question

我有一个简单的table像这样

firstname, lastname , nb_payments
a, b , 10
a, b , 20
b, a , 30
b, a , 40
b, b , 50

我想select按夫妻名字、姓氏分组的 3 笔最高付款

想要的输出是这样的

firstname, lastname , top3
b, a , 70
b, b , 50
a, b , 30

我做了这个查询：SELECT firstname, lastname , nb_payments as top3 FROM account ORDER BY nb_payments DESC LIMIT 3

但它并没有加起来 nb_payments 按夫妇名字、姓氏分组

如有任何帮助，我们将不胜感激非常感谢

Answer 1

您需要按 firstname 和 lastname

对付款进行汇总和分组

SELECT   firstname, lastname , SUM(nb_payments) 
FROM     account 
GROUP BY firstname, lastname
ORDER BY 3 DESC LIMIT 3

Answer 2

我认为这会产生您想要的输出：

select firstname, lastname, sum(nb_payments)
from (select t.*,
             row_number() over (partition by firstname, lastname
                                order by nb_payments desc) as seqnum
      from table t
     ) t
where seqnum <= 3
group by firstname, lastname;

Answer 3

这就是我在 oracle 中的写法，如果有帮助的话。还有其他方法。

select * from(
    SELECT firstname, lastname , sum(nb_payments) as top3 FROM test group by firstname,lastname ORDER BY top3 desc )
    where rownum <=3

选择按两列分组的最大值

selecting max values grouped by two column

sql

postgresql

greatest-n-per-group