Mysql组从表中限制数据

Question

我有一个帐户表我希望获取在3个最大交易中获得大于或等于1024金额的所有收件人姓名。

我附加一张图片来展示表中的数据，这些结果将是两行，收件人名称为nutan和vicky

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select recipient from accounts group by recipient having sum(amount) >= 1024 and count(*) <=3

Answer 1

您需要获得前三个交易。可能最简单的方法是使用变量：

select recipient
from (select a.*,
             (@rn := if(@r = recipient, @rn + 1,
                        if(@rn := recipient, 1, 1)
                       )
             ) as rn
      from accounts a cross join
           (select @rn := 0, @r := '') params
      order by recipient, amount desc
     ) a
where rn <= 3
group by recipient
having sum(amount) >= 1024;

Answer 2

我发现解决方案现在感觉像超级英雄。

set @num=1,@recp:='';
select 
@recp:=recipient as recipient
from 
(select recipient,amount from accounts order by recipient,amount desc) as accounts
where (@num:=if(@recp=recipient,@num+1,1))<4
group by recipient
having sum(amount)>=1024
order by recipient,amount desc;