Question

我的SQL查询可以显示以下结果：

Name   Project       Date
Peter    A           2014-12-11
Peter    C           2014-12-12
Peter    D           2014-12-13
John     B           2014-12-12

我想显示如下结果。（未显示相同的名称）

Name     Project           Date
Peter       A            2014-12-11
            C            2014-12-12
            D            2014-12-13
John        B            2014-12-12

我的数据库服务器是MS SQL Server 2012 Standard。如何通过SQL查询获得上述结果？

谢谢，

贝

Answer 1

使用window Function查找每个组中的第一个日期（名称）

SELECT CASE WHEN rn = 1 THEN Name ELSE '' END Name,
       Project,
       Dates
FROM   (SELECT Row_number()OVER (partition BY Name ORDER BY Dates) rn,*
        FROM   Tablename) a

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Answer 2

您可以使用ROW_NUMBER()功能

执行以下操作

;WITH CTE AS
(
   SELECT Name As OldName, Project, Date, 
          Row_Number() OVER (Partition By Name Order By Project) rn
   From YourTable
)
SELECT CASE WHEN rn = 1 THEN OldName ELSE '' End Name, Project, Date
FROM CTE
ORDER BY OldName, rn

Answer 3

SELECT  CASE WHEN ROW_NUMBER() OVER ( PARTITION BY Name ORDER BY Name ) = 1
             THEN Name
             ELSE ''
        END AS Name ,
        Project ,
        Date
FROM    t1

更改SQL显示结果（按名称分组）

3 个答案:

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