MySQL按分组统计最小值

Question

以下是表格数据（一个小片段），我想查询按账户号分组时具有最小original_date_ctr的行。

我尝试使用HAVING(MIN())，where = Min()和其他方法都没有成功。

正确的结果应该给出id_ctr 688、1204和1209。

id_ctr  account_number_cus  original_date_ctr   mrc_ctr  
------  ------------------  -----------------  ----------
   688               20062  2008-05-17             138.97
  1204              151604  2006-08-10           42000.00
  1209              151609  2006-06-29             968.68
  1367               20062  2011-10-27             207.88
  1434              151609  2009-09-10            1469.62
  1524              151604  2009-09-01           36999.99
  1585              151609  2012-05-31            1683.88

- bbutle01

Answer 1

使用join操作会更快：

SELECT a.*
FROM mytable a
LEFT JOIN mytable b
  ON a.account_number_cus = b.account_number_cus
  AND b.original_date_ctr < a.original_date_ctr
WHERE b.id_ctr IS NULL

- Chronial

---

这应该是被认可的答案，MySQL中的派生表会降低性能。 - Andrea Sprega

Answer 2

您可以按照以下方式完成此操作：

select t1.id_ctr,
    t1.account_number_cus,
    t1.original_date_ctr,
    t1.mrc_ctr  
from yourtable t1
inner join
(
    select min(original_date_ctr) as mindate, account_number_cus
    from yourtable
    group by account_number_cus
) t2
    on t1.account_number_cus = t2.account_number_cus
    and t1.original_date_ctr = t2.mindate

请查看带演示的SQL Fiddle：此处。

- Taryn