SQL從同一表中選擇具有最大行的三行，然后與第二個表聯接

Question

我覺得最大的atraso每個合同，但我也不能提取NUM_PARCELA ，只有contrato通過，因為我組contrato 。
任何建議，以提取num_parcela ， max_atraso每個contrato ？

Select  
   a.[CONTRATO]
  ,a.[NUM_PARCELA]
  ,a.[DATA_PAGAMENTO]
  ,a.[DATA_VENCTO]
  ,b.[DATA_LIBER_CONTRATO]
  ,DATEDIFF(day, a.DATA_VENCTO, a.DATA_PAGAMENTO) as ATRASO
 INTO #temp1
  from [fprisco].[dbo].[ParcelasGrc2] as a   
inner join [fprisco].[dbo].[ContratosGrc2] as b     
on b.contrato=a.contrato   
where b.data_liber_contrato >'2017-02-28 00:00:00.000'

Select    
   contrato,   
   max(atraso) as Max_Atraso        
   from #temp1     
group by contrato  
 order by contrato desc 

我需要的是最大atraso每個contrato ，並采取哪些num_parcela與最大匹配atraso 。 Num_Parcela具有每個合同的多個記錄，並且只有一個具有最大atraso匹配atraso 。

Answer 1

有更多方法可以執行此操作，請參見以下兩種方法：

測試用例：

DECLARE @temp1 TABLE (contrato int, atraso int, num_parcela int)

INSERT INTO @temp1 VALUES (1,5,1)
INSERT INTO @temp1 VALUES (1,4,2)
INSERT INTO @temp1 VALUES (1,3,3)
INSERT INTO @temp1 VALUES (2,2,1)
INSERT INTO @temp1 VALUES (2,3,1)
INSERT INTO @temp1 VALUES (2,4,2)

具有分組依據的第一個變體，並返回到原始表

;WITH MaxAtraso AS (
    Select    
       contrato,   
       max(atraso) as Max_Atraso   
    from @temp1     
    group by contrato  
)
SELECT m.*, t.num_parcela FROM MaxAtraso m 
JOIN @temp1 t 
ON m.Max_Atraso = t.atraso AND m.contrato = t.contrato
ORDER BY contrato DESC

使用ROW_NUMBER（）排序列表的第二個變體：

;WITH OrderByAtraso AS (
    Select    
       contrato,  
       num_parcela,
       atraso,
       ROW_NUMBER() OVER (PARTITION BY contrato ORDER BY atraso DESC) rn
    from @temp1     
)
SELECT * FROM OrderByAtraso WHERE RN=1 ORDER BY contrato DESC

同樣，無需為此操作創建臨時表，您可以像這樣重寫：

;WITH OrderByAtraso AS (
Select  
   a.[CONTRATO]
  ,a.[NUM_PARCELA]
  ,a.[DATA_PAGAMENTO]
  ,a.[DATA_VENCTO]
  ,b.[DATA_LIBER_CONTRATO]
  ,DATEDIFF(day, a.DATA_VENCTO, a.DATA_PAGAMENTO) as ATRASO
  ,ROW_NUMBER() OVER (
       PARTITION BY contrato 
       ORDER BY DATEDIFF(day, a.DATA_VENCTO, a.DATA_PAGAMENTO) DESC) RN
from [fprisco].[dbo].[ParcelasGrc2] as a   
inner join [fprisco].[dbo].[ContratosGrc2] as b     
on b.contrato=a.contrato   
where b.data_liber_contrato >'20170228'
)
SELECT contrato, atraso as MaxAtraso, num_parcela
FROM OrderByAtraso WHERE RN=1 ORDER BY CONTRATO DESC