sql server - transforming data with dynamic pivot [duplicate] - sql-server

Question

This question already has answers here:
SQL Server dynamic PIVOT query?
(9 answers)
Closed 7 years ago.
I need to dynamically transform data in table #table from this format:
spot_id name pct
------- ---- ---
1 A 2
1 B 8
1 C 6
2 A 4
2 B 5
3 A 5
3 D 1
3 E 4
to:
spot_id A B C D E
------- --- --- --- --- ---
1 2 5 6 0 0
2 4 5 0 0 0
3 5 0 0 1 4
The thing is that I don't know in advance what the values of column "name" are or how many of them there are, so I think that I have to use some kind of dynamic SQL pivoting
Just figured out how to solve the problem:
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT ',' + QUOTENAME(name)
from (SELECT DISTINCT name FROM #table) T
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = N'SELECT spot_id,' + #cols + N' from
(
select spot_id, name, pct
from #table
) as x
pivot
(
max(pct)
for name in (' + #cols + N')
) as p '
exec sp_executesql #query;
If there more elegant way to do the same?

Answer 1

declare #t table (Spot int,name varchar(1),pct int)
insert into #t(Spot,name,pct)values(1,'A',2),(1,'B',8),(1,'C',6),(2,'A',4),(2,'B',5),(3,'A',5),(3,'D',1),(3,'E',4)
select Spot,ISNULL([A],0)[A],ISNULL([B],0)[B],ISNULL([C],0)[C],ISNULL([D],0)[D],ISNULL([E],0)[E] from (Select Spot,PCT,Name from #t)T
PIVOT(MAX(PCT) FOR Name IN ([A],[B],[C],[D],[E]))P
select Spot,ISNULL(MAX(CASE WHEN name = 'A' THEN pct END),0)A,ISNULL(MAX(CASE WHEN name = 'B' THEN pct END),0)B ,
ISNULL(MAX(CASE WHEN name = 'C' THEN pct END),0)C ,
ISNULL(MAX(CASE WHEN name = 'D' THEN pct END),0)D ,ISNULL(MAX(CASE WHEN name = 'E' THEN pct END),0)E from #t
GROUP BY Spot
Using Dynamic Query :
if object_id('tempdb..#t') is not null
drop table #t
CREATE table #t(Spot int,name varchar(1),pct int)
insert into #t(Spot,name,pct)values(1,'A',2),(1,'B',8),(1,'C',6),(2,'A',4),(2,'B',5),(3,'A',5),(3,'D',1),(3,'E',4)
DECLARE #statement NVARCHAR(max)
,#columns NVARCHAR(max)
SELECT #columns = ISNULL(#columns + ', ', '') + N'[' + tbl.name + ']'
FROM (
SELECT DISTINCT name
FROM #t
) AS tbl
SELECT #statement = ' select Spot,ISNULL([A],0)[A],ISNULL([B],0)[B],ISNULL([C],0)[C],ISNULL([D],0)[D],ISNULL([E],0)[E] from (Select Spot,PCT,Name from #t)T
PIVOT(MAX(PCT) FOR Name IN (' + #columns + ')) as pvt'
EXEC sp_executesql #statement = #statement