Question

我需要找到Ten_Yr_CAPE没有0值的第一个日期。当Ten_Yr_CAPE大于0时，输出表应具有Country列和Date Column，其中包含Date。

我写了下面的查询，但是它提取了所有包含＆＃39; Ten_Yr_CAPE＆＃39; ＆LT;＆GT;我只需要初始日期。任何人都可以帮助我。

选择TOP（1）只返回一条记录。我需要每个国家一条记录。所以每个国家共有20条记录

    select  [Date],[Country] from [Tableau].[dbo].[Country_table4$] where 
    [Ten_Yr_CAPE] <> 0 
     Group by [Country], [Date]
     Order by [Date] ASC

Answer 1

我认为聚合是最简单的方法：

select  t.[Country], min(t.[Date])
from [Tableau].[dbo].[Country_table4$] t
where [Ten_Yr_CAPE] <> 0 
Group by [Country]
Order by [Date] ASC

Answer 2

SELECT *
FROM (     
     SELECT *, ROW_NUMBER() OVER (PARTITION BY [COUNTRY]
                                  ORDER BY [Date]) as rn
     FROM [Tableau].[dbo].[Country_table4$] 
     WHERE [Ten_Yr_CAPE] <> 0 ) AS T
WHERE T.rn = 1

Answer 3

你可以使用top（1）with ties：

select top (1) with ties  [Date],[Country]
from [Tableau].[dbo].[Country_table4$]
where [Ten_Yr_CAPE] <> 0 
order by row_number() over(partition by [Country] order by [Date] ASC)

如何找到值不等于零的第一行

3 个答案: