How to pivot rows into colums dynamically SQL Server - sql

Question

I have a request which returns something like this:
--------------------------
Tool | Week | Value
--------------------------
Test | 20 | 3
Sense | 20 | 2
Test | 19 | 2
And I want my input to look like this:
-------------------------
Tool | W20 | W19
-------------------------
Test | 3 | 2
Sense | 2 | null
Basically, for every week I need to have a new column. The number of week and of tools is dynamic.
I have tried many things but nothing worked. Anybody have a solution ?

Answer 1

Try this
CREATE table #tst (
Tool varchar(50), [Week] int, Value int
)
insert #tst
values
('Test', 20, 3),
('Sense', 20,2),
('Test', 19, 2)
Here is the Dynamic Query:
DECLARE #col nvarchar(max), #query NVARCHAR(MAX)
SELECT #col = STUFF((SELECT DISTINCT ',' + QUOTENAME('W' + CAST([Week] as VARCHAR))
from #tst
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
SET #query = '
SELECT *
FROM (
SELECT Tool,
Value,
''W'' + CAST([Week] as VARCHAR) AS WeekNo
FROM #tst
) t
PIVOT
(
MAX(t.Value)
FOR WeekNo IN (' + #col + ')
) pv
ORDER by Tool'
EXEC (#query)
Result
Tool W20 W19
=================
Sense 2 NULL
Test 3 2

Answer 2

IF OBJECT_ID('tempdb..#temp') IS NOT NULL
DROP TABLE #temp
CREATE TABLE #temp
( Tool varchar(5), Week int, Value int)
;
INSERT INTO #temp
( Tool , Week , Value )
VALUES
('Test', 20, 3),
('Sense', 20, 2),
('Test', 19, 2)
;
DECLARE #statement NVARCHAR(max)
,#columns NVARCHAR(max),
#col NVARCHAR(max)
SELECT #columns = ISNULL(#columns + ', ', '') + N'[' +'w'+ tbl.[Week] + ']'
FROM (
SELECT DISTINCT CAST([Week] AS VARCHAR)[Week]
FROM #temp
) AS tbl
SELECT #statement = 'SELECT *
FROM
(
SELECT
Tool , ''w''+ CAST(Week AS VARCHAR) week , Value
FROM
#Temp
) src
PIVOT(MAX(Value)for Week in (' + #columns + ')) as pvt
'
EXEC sp_executesql #statement = #statement

Answer 3

This is how I would do it ... If I understood your question correctly
if object_id('tempdb..#InputTool') is not null drop table #InputTool
create table #InputTool (Tool nvarchar(10), [20] int, [19] int)
insert into #InputTool (Tool, [20], [19])
values
('Test', 3, 2),
('Sense', 2, null)
declare #cols nvarchar(max)
select #cols = STUFF((SELECT ',' + QUOTENAME(name)
from tempdb.sys.columns
where object_id = object_id('tempdb..#InputTool')
and Column_id > 1
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
declare #sqlquery nvarchar(max) =
'select Tool, Weeks, Value from (
select * from #InputTool
) as it
UNPIVOT
(
Value FOR Weeks IN (' + #cols + ')
) AS Weeks
order by Weeks desc'
execute (#sqlquery);
Give it a shot and let me know if it worked