如何在SQL中获取复合数据的最大值？

Question

SELECT "Name""Month","Year","Value" 
from Table 
WHERE 
    "Name" LIKE '%JERRY%' 
AND "Year" = 
    (SELECT MAX("Year") FROM Table where "Name" LIKE '%JERRY%') 
AND "Month"= 
    (SELECT MAX("Month") FROM Table 
    where 
     "Name" LIKE '%JERRY%' 
    AND "Year"= (SELECT MAX("Year") FROM Table where "Name" LIKE '%JERRY%')) 

表 - >

Name | Year | Month | Value 
----------------------------- 
JERRY 2012 9  100   
JERRY 2012 9  120   
JERRY 2012 9  130   
JERRY 2012 8   20   
JERRY 2011 12  50   

所以我想排前三作为输出。至于最近一年的最新月份，我需要所有的价值。 有人可以建议更清洁的查询吗？

Answer 1

如果有其他人在表中，那么你可能想使用排序功能：是这样的：

DECLARE @sample TABLE (
     [Name] VARCHAR(255) 
    , [Year] INT 
    , [Month] INT 
    , [Value] INT 
    ) 

INSERT @sample ([Name], [Year], [Month], [Value]) 
VALUES ('JERRY', 2012, 9, 100)   
    , ('JERRY', 2012, 9, 120) 
    , ('JERRY', 2012, 9, 130) 
    , ('JERRY', 2012, 8, 20) 
    , ('JERRY', 2011, 12, 50) 
    , ('FRED', 2011, 12, 50) 
    , ('FRED', 2011, 12, 120) 
    , ('FRED', 2011, 7, 150) 

SELECT * 
FROM (
    SELECT * 
     , RANK() OVER (PARTITION BY [Name] ORDER BY [Year] DESC, [Month] DESC) AS [rnk] 
    FROM @sample 
    ) 
    AS samp 
WHERE 
    samp.[rnk] = 1 

其中给出的结果：

 
Name      Year  Month  Value  rnk 
------------------------- ----------- ----------- ----------- ------ 
FRED      2011  12   50   1 
FRED      2011  12   120   1 
JERRY      2012  9   100   1 
JERRY      2012  9   120   1 
JERRY      2012  9   130   1 

Answer 2

select * from @t where 
[Year] = (select max([year]) from @t) and 
[Month] = (select max([Month]) from @t where [Year]=(select max([year]) from @t)) 

Answer 3

DECLARE @t Table(Name Varchar(30),[Year] Int, [Month] Int,Value Int) 
Insert Into @t Values('JERRY' , 2012, 9,  100) 
Insert Into @t Values('JERRY', 2012, 9 ,  120)   
Insert Into @t Values('JERRY' , 2012, 9 ,  130)   
Insert Into @t Values('JERRY', 2012 , 8 ,  20)   
Insert Into @t Values('JERRY', 2011, 12 ,  50) 


Declare @LatestYr Int 
Declare @LatestMonth Int 

Select @LatestYr= Max([Year])From @t 
Select @LatestMonth = Max([Month]) From @t Where [Year] = @LatestYr 

Select * From @t 
Where ([Year] = @LatestYr And [Month] = @LatestMonth) 

结果

上述查询的工作只是为单个用户。并且会失败多个用户，或在关系的情况下。例如，请考虑下面的情形

在这种情况下，所需的输出将是

所以对于处理这样的情况，我建议以下解决方案

解决方案1 ​​

Select t.* 
From @t t 
Join 
(
    Select x.Name,x.Max_Year,y.Max_Month 
    From 
     ( SELECT Name,Max_Year = Max([Year]) 
      From @t 
      Group By Name 
     )x 
    Join 
     ( SELECT Name,[Year],Max_Month= Max([Month]) 
      From @t 
      Group By Name,[Year] 
     )y On x.Name = y.Name And x.Max_Year = y.[Year] 
)x 
On t.Name = x.Name 
And t.[Year] = x.Max_Year 
And t.[Month] = x.Max_Month 

OR

溶液2（SQL服务器2005+）

Select Name,[Year],[Month],Value 
From 
(
    Select *,Rn = Rank() Over(Partition By Name Order By [Year] desc, [Month] Desc) 
    From @t 
)X Where X.Rn =1 

溶液3（SQL服务器2005+）

Select Name,[Year],[Month],Value 
From 
(
    Select *,Rn = Dense_Rank() Over(Partition By Name Order By [Year] desc, [Month] Desc) 
    From @t 
)X Where X.Rn =1 

的DDL是

下

DECLARE @t Table(Name Varchar(30),[Year] Int, [Month] Int,Value Int) 
Insert Into @t Values('JERRY' , 2012, 9,  100) 
Insert Into @t Values('JERRY', 2012, 9 ,  120)   
Insert Into @t Values('JERRY' , 2012, 9 ,  130)   
Insert Into @t Values('JERRY', 2012 , 8 ,  20)   
Insert Into @t Values('JERRY', 2011, 12 ,  50) 
Insert Into @t Values('FERRY' , 2010, 9,  100) 
Insert Into @t Values('FERRY', 2010, 9 ,  120) 
Insert Into @t Values('FERRY', 2010, 8 ,  120) 
Insert Into @t Values('JERRY1' , 2012, 9,  100) 
Insert Into @t Values('JERRY1', 2012, 9 ,  120)   
Insert Into @t Values('JERRY1' , 2012, 9 ,  130)   
Insert Into @t Values('JERRY1', 2012 , 8 ,  20)   
Insert Into @t Values('JERRY1', 2011, 12 ,  50) 

希望这可能有所帮助。由于

Answer 4

select * 
from your_table 
where "Name" LIKE '%JERRY%' 
and  year*100+month 

in(
    select top 1 year*100+month 
    from your_table 
    where 
    "Name" LIKE '%JERRY%' 
    order by cast(year*100+month as int) desc) 

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