蜂巢表達不在組

Question

我的表架構的（國家字符串，市字符串，大小INT）

這裏是我的輸入數據

Karnataka,Bangalore,200 
Karnataka,Mysore,50 
Karnataka,Bellary,100 
Karnataka,Mangalore,10 
Andhra pradesh,Chittoor, 25 
Andhra pradesh,nellore, 15 
Andhra pradesh,guntur, 20 
Andhra pradesh,tirupathi, 30 
Andhra pradesh,vizag, 35 
Andhra pradesh,kadapa, 45 

我想要檢索的頂部2全市狀態隨着大小，我想輸出如下。

(Andhra pradesh,{(35),(30)},{(vizag),(tirupathi)}) 
(Karnataka,{(200),(100)},{(Bangalore),(Bellary)}) 

我已經寫了下面的查詢，但我得到錯誤作爲表達式不按大小組，PLZ幫助我。

select * from statefile groyp by state,city order by size limit 2; 

在此先感謝。

Answer 1

你會使用row_number()：

select sf.* 
from (select sf.*, 
      row_number() over (partition by state order by size desc) as seqnum 
     from statefile sf 
    ) sf 
where seqnum <= 2;