如何从表中选择最大当前值

Question

    SELECT
    credit_detail.bill_id,
    credit_detail.credit_id
    FROM credit_detail
   WHERE credit_detail.credit_id=(SELECT max(credit_id)FROM credit_detail )

输入：

bill_id credit_id
 2 4 
 6 8 
 2 17 
 6 12

预期

Bill_id credit_id 
 2 17 
 6 12

Answer 1

您可以在bill_id上执行group by以获得最大的credit_id，如下所示：

select 
  bill_id,
  max(credit_id) credit_id
from credit_details
group by bill_id

如果credit_details中有更多列要获取max credit_id，请使用：

select c1.*
credit_details c1 inner join (
    select bill_id, max(credit_id) credit_id
    from credit_details
    group by bill_id
) c2 on c1.bill_id = c2.bill_id
    and c1.credit_id = c2.credit_id;