SQL Server : dynamic pivot over 5 columns - sql

Question

I'm having a very tough time trying to figure out how to do a dynamic pivot in SQL Server 2008 with multiple columns.
My sample table is as follows:
ID YEAR TYPE TOTAL VOLUME
DD1 2008 A 1000 10
DD1 2008 B 2000 20
DD1 2008 C 3000 30
DD1 2009 A 4000 40
DD1 2009 B 5000 50
DD1 2009 C 6000 60
DD2 2008 A 7000 70
DD2 2008 B 8000 80
DD2 2008 C 9000 90
DD2 2009 A 10000 100
DD2 2009 B 11000 110
DD2 2009 C 12000 120
and I'm trying the pivot it as follows:
ID 2008_A_TOTAL 2008_A_VOLUME 2008_B_TOTAL 2008_B_VOLUME 2008_C_TOTAL 2008_C_VOLUME 2009_A_TOTAL 2009_A_VOLUME 2009_B_TOTAL 2009_B_VOLUME 2009_C_TOTAL 2009_C_VOLUME
DD1 1000 10 2000 20 3000 30 4000 40 5000 50 6000 60
DD2 7000 70 8000 80 9000 90 10000 100 11000 110 12000 120
My SQL Server 2008 query is as follows to create the table:
CREATE TABLE ATM_TRANSACTIONS
(
ID varchar(5),
T_YEAR varchar(4),
T_TYPE varchar(3),
TOTAL int,
VOLUME int
);
INSERT INTO ATM_TRANSACTIONS
(ID,T_YEAR,T_TYPE,TOTAL,VOLUME)
VALUES
('DD1','2008','A',1000,10),
('DD1','2008','B',2000,20),
('DD1','2008','C',3000,30),
('DD1','2009','A',4000,40),
('DD1','2009','B',5000,50),
('DD1','2009','C',6000,60),
('DD2','2008','A',7000,70),
('DD2','2008','B',8000,80),
('DD2','2008','C',9000,90),
('DD2','2009','A',10000,100),
('DD2','2009','B',11000,110),
('DD2','2009','C',1200,120);
The T_Year column may change in the future but the T_TYPE column is generally know, so I'm not sure if I can use a combination of the PIVOT function in SQL Server with dynamic code?
I tried following the example here:
http://social.technet.microsoft.com/wiki/contents/articles/17510.t-sql-dynamic-pivot-on-multiple-columns.aspx
but I ended up with with weird results.

Answer 1

In order to get the result, you will need to look at unpivoting the data in the Total and Volume columns first before applying the PIVOT function to get the final result. My suggestion would be to first write a hard-coded version of the query then convert it to dynamic SQL.
The UNPIVOT process converts these multiple columns into rows. There are a few ways to UNPIVOT, you can use the UNPIVOT function or you can use CROSS APPLY. The code to unpivot the data will be similar to:
select id,
col = cast(t_year as varchar(4))+'_'+t_type+'_'+col,
value
from ATM_TRANSACTIONS t
cross apply
(
select 'total', total union all
select 'volume', volume
) c (col, value);
This gives you data in the format:
+-----+---------------+-------+
| id | col | value |
+-----+---------------+-------+
| DD1 | 2008_A_total | 1000 |
| DD1 | 2008_A_volume | 10 |
| DD1 | 2008_B_total | 2000 |
| DD1 | 2008_B_volume | 20 |
| DD1 | 2008_C_total | 3000 |
| DD1 | 2008_C_volume | 30 |
+-----+---------------+-------+
Then you can apply the PIVOT function:
select ID,
[2008_A_total], [2008_A_volume], [2008_B_total], [2008_B_volume],
[2008_C_total], [2008_C_volume], [2009_A_total], [2009_A_volume]
from
(
select id,
col = cast(t_year as varchar(4))+'_'+t_type+'_'+col,
value
from ATM_TRANSACTIONS t
cross apply
(
select 'total', total union all
select 'volume', volume
) c (col, value)
) d
pivot
(
max(value)
for col in ([2008_A_total], [2008_A_volume], [2008_B_total], [2008_B_volume],
[2008_C_total], [2008_C_volume], [2009_A_total], [2009_A_volume])
) piv;
Now that you have the correct logic, you can convert this to dynamic SQL:
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT ',' + QUOTENAME(cast(t_year as varchar(4))+'_'+t_type+'_'+col)
from ATM_TRANSACTIONS t
cross apply
(
select 'total', 1 union all
select 'volume', 2
) c (col, so)
group by col, so, T_TYPE, T_YEAR
order by T_YEAR, T_TYPE, so
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = 'SELECT id,' + #cols + '
from
(
select id,
col = cast(t_year as varchar(4))+''_''+t_type+''_''+col,
value
from ATM_TRANSACTIONS t
cross apply
(
select ''total'', total union all
select ''volume'', volume
) c (col, value)
) x
pivot
(
max(value)
for col in (' + #cols + ')
) p '
execute sp_executesql #query;
This will give you a result:
+-----+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+
| id | 2008_A_total | 2008_A_volume | 2008_B_total | 2008_B_volume | 2008_C_total | 2008_C_volume | 2009_A_total | 2009_A_volume | 2009_B_total | 2009_B_volume | 2009_C_total | 2009_C_volume |
+-----+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+
| DD1 | 1000 | 10 | 2000 | 20 | 3000 | 30 | 4000 | 40 | 5000 | 50 | 6000 | 60 |
| DD2 | 7000 | 70 | 8000 | 80 | 9000 | 90 | 10000 | 100 | 11000 | 110 | 1200 | 120 |
+-----+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+

Answer 2

declare #stmt nvarchar(max)
select #stmt = isnull(#stmt + ', ', '') +
'sum(case when T_YEAR = ''' + T.T_YEAR + ''' and T_TYPE = ''' + T.T_TYPE + ''' then TOTAL else 0 end) as ' + quotename(T.T_YEAR + '_' + T.T_TYPE + '_TOTAL') + ',' +
'sum(case when T_YEAR = ''' + T.T_YEAR + ''' and T_TYPE = ''' + T.T_TYPE + ''' then VOLUME else 0 end) as ' + quotename(T.T_YEAR + '_' + T.T_TYPE + '_VOLUME')
from (select distinct T_YEAR, T_TYPE from ATM_TRANSACTIONS) as T
order by T_YEAR, T_TYPE
select #stmt = '
select
ID, ' + #stmt + ' from ATM_TRANSACTIONS group by ID'
exec sp_executesql
#stmt = #stmt
unfortunately, sqlfiddle.com is not working at the moment, so I cannot create an example for you.
The query created by dynamic SQL would be:
select
ID,
sum(case when T_YEAR = '2008' and T_TYPE = 'A' then TOTAL else 0 end) as 2008_A_TOTAL,
sum(case when T_YEAR = '2008' and T_TYPE = 'A' then VOLUME else 0 end) as 2008_A_VOLUME,
...
from ATM_TRANSACTIONS
group by ID

Answer 3

Please try:
DECLARE #pivv NVARCHAR(MAX),#Query NVARCHAR(MAX)
SELECT #pivv=COALESCE(#pivv+',','')+ QUOTENAME(T_YEAR+'_'+T_TYPE+'_TOTAL')+','+QUOTENAME(T_YEAR+'_'+T_TYPE+'_VOLUME') from ATM_TRANSACTIONS GROUP BY T_YEAR, T_TYPE
IF ISNULL(#pivv, '')<>''
SET #Query='SELECT * FROM(
SELECT ID, T_YEAR+''_''+T_TYPE+''_TOTAL'' TYP, TOTAL VAL from ATM_TRANSACTIONS UNION
SELECT ID, T_YEAR+''_''+T_TYPE+''_VOLUME'' TYP, VOLUME VAL from ATM_TRANSACTIONS
)x pivot (SUM(VAL) for TYP in ('+#pivv+')) as xx'
IF ISNULL(#Query, '')<>''
EXEC (#Query)