選擇使用MAX和組的所有相應的字段BY

Question

我有這個表：

，我想提出，將返回每個deal_id最高timestamp，和該行的請求相應的status_id。

所以在這個例子中，我將返回2行：

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

我試圖與此查詢

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

做到這一點，但它會返回錯誤status_id：

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

Answer 1

沒有一個主鍵字段，我認爲你最好的選擇是：

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 

這個，如果你允許具有同時

Answer 2

嗨，我希望這同一產品兩種不同的狀態仍然無法工作給予什麼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