SQL Server 2008 R2——ROW_NUMBER() 去掉不同行中相同列的重复内容

USE tempdb
GO
--------------------------------------------------------------------------
IF OBJECT_ID(‘Student‘,‘U‘) IS NOT NULL
DROP TABLE Student
GO

CREATE TABLE Student
(
    StuID NVARCHAR(8) PRIMARY KEY,
    Name NVARCHAR(5),
    EntranceTime DATETIME
)
GO

INSERT INTO Student(StuID,Name,EntranceTime) VALUES(‘20080001‘,‘Lily‘,‘2008-08-27‘)
INSERT INTO Student(StuID,Name,EntranceTime) VALUES(‘20090002‘,‘Lucy‘,‘2009-08-26‘)
INSERT INTO Student(StuID,Name,EntranceTime) VALUES(‘20070003‘,‘Jack‘,‘2007-08-28‘)
GO
--------------------------------------------------------------------------
IF OBJECT_ID(‘SltCourse‘,‘U‘) IS NOT NULL
DROP TABLE SltCourse
GO

CREATE TABLE SltCourse    --SelectiveCourse
(
    ID INT PRIMARY KEY IDENTITY(1,1),
    StuID NVARCHAR(8),
    CourseName NVARCHAR(10),
    Score    INT 
)
GO

INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20070003‘,‘电脑维修‘,90)
INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20070003‘,‘剪纸‘,80)
INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20070003‘,‘市场策划‘,95)
INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20070003‘,‘信息检索‘,100)

INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20080001‘,‘插花‘,99)
INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20080001‘,‘剪纸‘,96)
INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20080001‘,‘刺绣‘,92)

INSERT INTO SltCourse(StuID,CourseName,Score) VALUES(‘20090002‘,‘插花‘,98)
GO
--------------------------------------------------------------------------
SELECT * FROM Student
GO
SELECT * FROM SltCourse
GO
--------------------------------------------------------------------------
SELECT * FROM Student s,SltCourse sc WHERE s.stuid=sc.stuid
GO
--------------------------------------------------------------------------
WITH ReportCard 
AS(
SELECT s.StuID,s.Name,s.EntranceTime,sc.CourseName,sc.Score FROM Student s,SltCourse sc WHERE s.stuid=sc.stuid
)
SELECT  CASE WHEN RowNum=1 THEN StuID         　ELSE ‘‘ END AS ID,
        CASE WHEN RowNum=1 THEN Name            ELSE ‘‘ END AS Name,
        CASE WHEN RowNum=1 THEN EntranceTime    ELSE ‘‘ END AS EntranceTime,
        CourseName,
        Score
FROM (SELECT *,ROW_NUMBER()  OVER (PARTITION BY StuID,Name,EntranceTime ORDER BY Score) AS RowNum FROM ReportCard) TBL
GO
--------------------------------------------------------------------------
DROP TABLE Student
GO
DROP TABLE SltCourse
GO

WITH ReportCard 
AS(
SELECT s.StuID,s.Name,s.EntranceTime,sc.CourseName,sc.Score FROM Student s,SltCourse sc WHERE s.stuid=sc.stuid
)
SELECT  CASE WHEN RowNum=1 THEN StuID         　ELSE ‘‘ END AS ID,
        CASE WHEN RowNum=1 THEN Name            ELSE ‘‘ END AS Name,
        CASE WHEN RowNum=1 THEN EntranceTime    ELSE cast(nullif(‘‘,‘‘) as datetime) END AS EntranceTime,
        CourseName,
        Score
FROM (SELECT *,ROW_NUMBER()  OVER (PARTITION BY StuID,Name,EntranceTime ORDER BY Score) AS RowNum FROM ReportCard) TBL
GO