选择使用MAX和组的所有相应的字段BY

Question

我有这个表：

，我想提出，将返回每个deal_id最高timestamp，和该行的请求相应的status_id。

所以在这个例子中，我将返回2行：

1226, 3, 2009-08-18 12:10:25 
1227, 2, 2009-08-17 14:31:25 

我试图与此查询

SELECT deal_id, status_id, max(timestamp) FROM deal_status GROUP BY deal_id 

做到这一点，但它会返回错误status_id：

1226, 1, 2009-08-18 12:10:25 
1227, 1, 2009-08-17 14:31:25 

Answer 1

没有一个主键字段，我认为你最好的选择是：

select * from deal_status 
inner join 
    (select deal_id as did, max(timestamp) as ts 
    from deal_status group by deal_id) as ds 
    on deal_status.deal_id = ds.did and deal_status.timestamp = ds.ts 

这个，如果你允许具有同时

Answer 2

嗨，我希望这同一产品两种不同的状态仍然无法工作给予什么ü希望它

select deal_id,status_id, timestamp from deal_status 
inner join 
    (select deal_id as did,max(timestamp) as ts 
    from deal_status group by deal_id )as ds 
    on deal_status.deal_id = ds.did and deal_status.timestamp = ds.ts order by deal_id