Question

任何建议都会很棒：

我正在运行MIN()查询，其中我的帐号具有相同的状态和两个不同的时间戳

例如：

SELECT 
  DATE(`created_at`) as date, 
  account_id, 
  changed_by_id, 
  status 
FROM statuses 
WHERE `changed_to` = 'entered' 
AND account_id = 49794;

结果：

date          account_id   changed_by_id  status
2011-04-05  49794        17             entered
2011-03-16  49794        18             entered

当我尝试提取min(DATE(created_at))和GROUP By account_id时，我找不到changed_by_id和account_id

的正确date

任何人都可以建议我需要对查询做些什么才能将date与changed_by_id匹配？

由于

Answer 1

未经测试，但它与此类似

select 
t1.DATE(`created_at`) as date, 
t1.account_id, 
t1.changed_by_id, 
t1.status 
from statuses t1
where  (date(created_at) = (select min(date(created_at))
              from statuses t2
              where t1.account_id=t2.account_id))
and t1.account_id = 49794;

Answer 2

按日期排序，并仅选择第一行：

SELECT 
  DATE(`created_at`) as date, 
  account_id, 
  changed_by_id, 
  status 
FROM statuses 
WHERE `changed_to` = 'entered' 
AND account_id = 49794
ORDER BY 1
LIMIT 1;

这可能不是最优雅的选择，但它既清晰又有效。

Mysql min查询

2 个答案: