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How do i transform rows into columns in sql server 2005

There is a question here in stackoverflow with the same title but that is not what I am looking for.
I have a table like the one below

Name   | Count  
----------------    
Chery  | 257  
Drew   | 1500
Morgon | 13  
Kath   | 500  
Kirk   | 200  
Matt   | 76 

I need to trasform this result set into something like this

Chery | Drew | Morgon | Kath | Kirk | Matt  
-------------------------------------------  
257     1500     13      500    200    76

How do i acheive this using sql server 2005?

like image 269
Sam Avatar asked Feb 26 '10 20:02

Sam


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1 Answers

There are similar questions here,here answered in stackoverflow.

You need to use the operator PIVOT in your query to acheive this.Here is the example and explanation on how you can do that.The example is referenced from this source.

---I assumed your tablename as TESTTABLE---
DECLARE @cols NVARCHAR(2000)
DECLARE @query NVARCHAR(4000)

SELECT  @cols = STUFF(( SELECT DISTINCT TOP 100 PERCENT
                                '],[' + t.Name
                        FROM    TESTTABLE AS t
                        ORDER BY '],[' + t.Name
                        FOR XML PATH('')
                      ), 1, 2, '') + ']'

SET @query = N'SELECT '+ @cols +' FROM
(SELECT t1.Name , t1.Count FROM TESTTABLE AS t1) p
PIVOT (MAX([Count]) FOR Name IN ( '+ @cols +' ))
AS pvt;'

EXECUTE(@query)

Explanation

1.The first part of the query

SELECT  @cols = STUFF(( SELECT DISTINCT TOP 100 PERCENT
                        '],[' + t.Name
                FROM TESTTABLE AS t
                ORDER BY '],[' + t.Name
                FOR XML PATH('')
              ), 1, 2, '') + ']'

gives you a nice flattened result of your Name column values in a single row as follow

[Cheryl],[Drew],[Karen],[Kath],[Kirk],[Matt]  

You can learn more about the STUFF and XML PATH here and here.

2.SELECT + @cols + FROM will select all the rows as coloumn names for the final result set (pvt - step 3)

i.e

Select [Chery],[Drew],[Morgan],[Kath],[Kirk],[Matt] 

3.This query pulls all the rows of data that we need to create the cross-tab results. The (p) after the query is creating a temporary table of the results that can then be used to satisfy the query for step 1.

(SELECT t1.Name, t1.Count FROM  TESTTABLE AS t1) p

4.The PIVOT expression

PIVOT (MAX (Count) FOR Name IN ( @cols) AS pvt

does the actual summarization and puts the results into a temporary table called pvt as

Chery | Drew | Morgon | Kath | Kirk | Matt  
-------------------------------------------  
257     1500     13      500    200    76
like image 175
I Am Back Avatar answered Oct 12 '22 23:10

I Am Back