Mysql的分查询

Question

任何意见将是巨大的：

我运行MIN()查询在那里我有同样的地位账号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我没有得到正确的changed_by_id是account_id和date

谁能指教一下，我需要通过查询获取匹配date与changed_by_id办？

感谢

Answer 1

未经测试，但它的日期与此类似

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

订购的东西，并且只选择第一行：

 
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; 

这可能不是最优雅选项，但它的理解和效率都很明显。