从表中的特定字段中选择最后一个值

Question

我想在SQL Server中编写一个脚本来显示输出表。

输入表

Name CompanyName ContractCode ContractEndDate 
---------------------------------------------------- 
A  B&D    A1   2016 08 31 
B  B&D    B1   2016 09 01 
B  B&D    C1   2016 09 02 
B  B&D    D1   2016 09 03 
C  B&D    E1   2016 09 04 
C  B&D    F1   2016 09 05 
C  B&D    G1   2016 09 06 
C  B&D    H1   2016 09 07 

输出应该是这样的：

Name CompanyName ContractCode ContractEndDate 
------------------------------------------------------ 
A  B&D    A1   2016 08 31 
B  B&D    D1   2016 09 03 
D  B&D    H1   2016 09 07 

我想显示所需的输出的SQL脚本。

Answer 1

的标准方法是使用row_number()：

select Name, CompanyName, ContractCode, ContractEndDate 
from (select t.*, 
      row_number() over (partition by Name order by ContractEndDate desc) as seqnum 
     from t 
    ) t 
where seqnum = 1; 

Answer 2

使用CTE：

;WITH CTE 
AS (
    SELECT *, 
      ROW_NUMBER() OVER (PARTITION BY Name ORDER BY ContractEndDate DESC) AS RN 
    FROM Inputtable 
    ) 

SELECT Name, CompanyName, ContractCode, ContractEndDate 
FROM CTE 
WHERE RN=1