Pivot SQL table with dynamic year columns - sql

Question

I'm having trouble figuring this out. I've checked similar posts but they only have one column as pivoted as a row. While I need to pivot
I have the following query:
SELECT
Year([Date]) as Year
,SUM([Drop]) as [Drop]
,SUM([TicketsDistributed]) as [TicketsDistributed]
,SUM([TicketsSold]) as [TicketsSold]
,SUM([GrossTickets]) as [GrossTickets]
,SUM([GrossTickets])/SUM(TicketsSold) as 'Per Cap'
FROM [dbo].[Tickets]
group by [Date]
Which give me this result:
Year Drop TicketsDistributed TicketsSold GrossTickets Per Cap
2016 222 100 5000 4000.00 0.800000
2015 222 110 5000 4000.00 0.900000
2014 222 120 5000 4000.00 1.00000
And I would like the following:
2016 2015 2014
Drop 222 222 222
TicketsDistributed 100 110 120
TicketsSold 5000 5000 5000
GrossTickets 4000 4000 4000
Per Cap 0.8 0.9 1
Based on the suggested answer this is what I have so far but it's not working
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT ',' + QUOTENAME(Year(Date))
from [dbo].[SpringTrainings] t
cross apply
(
select SUM([Drop]) as [Drop]
,SUM([TicketsDistributed]) as [TicketsDistributed]
,SUM([TicketsSold]) as [TicketsSold]
,SUM([GrossTickets]) as [GrossTickets]
,SUM([GrossTickets])/SUM(TicketsSold) as PerCap
FROM [dbo].[SpringTrainings]
) c ([Drop],[TicketsDistributed],[TicketsSold],[GrossTickets],PerCap)
group by Year(Date)
order by Year(Date)
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = 'SELECT [Drop],[TicketsDistributed],[TicketsSold],[GrossTickets],PerCap,' + #cols + '
from
(
select SUM([Drop]) as [Drop]
,SUM([TicketsDistributed]) as [TicketsDistributed]
,SUM([TicketsSold]) as [TicketsSold]
,SUM([GrossTickets]) as [GrossTickets]
,SUM([GrossTickets])/SUM(TicketsSold) as PerCap
FROM [dbo].[SpringTrainings]
) x
pivot
(
max(Year([Date]))
for Year([Date]) in (' + #cols + ')
) p '
execute sp_executesql #query;

Answer 1

If you wish to keep using the pivot operator within T-SQL, then first you need to "unpivot" your existing query so you have Year, Label, and Value. While there is an unpivot operator in T-SQL personally I find using CROSS APPLY and VALUES to be much simpler and equally as fast (for more on his approach read this article by Brad Schultz), I particularly like it because I can visualize the result easily by the way I layout the value pairs.
SELECT
d.Year
, a.label
, a.value
FROM (
SELECT
YEAR([Date]) AS [Year]
, SUM([Drop]) AS [Drop]
, SUM([TicketsDistributed]) AS [TicketsDistributed]
, SUM([TicketsSold]) AS [TicketsSold]
, SUM([GrossTickets]) AS [GrossTickets]
, SUM([GrossTickets]) / SUM(TicketsSold) AS [PerCap]
FROM [dbo].[Tickets]
GROUP BY
[Year]
) AS t
CROSS APPLY ( /* now transform into 5 rows per year but just 1 value column */
VALUES
('Drop',t.Drop)
, ('TicketsDistributed',t.TicketsDistributed)
, ('TicketsSold',t.TicketsSold)
, ('GrossTickets',t.GrossTickets)
, ('PerCap',t.PerCap)
) AS a (label, value)
That query (above) replaces the derived table x in your dynamic SQL. Once the data has been massaged into that form the pivot looks way simpler:
) x
pivot
(
max([x.Value])
for [x.Year] in ([2014],[2015],[2016])
) p
For your #cols I would suggest something simple like this:
SELECT DISTINCT
QUOTENAME(Year([date]))
FROM [dbo].[Tickets]
TIP: if you need a way to order the rows, include that in the cross apply too, like this:
CROSS APPLY ( /* now transform into 5 rows per year but just 1 value column */
VALUES
(1, 'Drop',t.Drop)
, (2, 'TicketsDistributed',t.TicketsDistributed)
, (3, 'TicketsSold',t.TicketsSold)
, (4, 'GrossTickets',t.GrossTickets)
, (5, 'PerCap',t.PerCap)
) AS a (row_order, label, value)
and then that [row_order] can be used after the pivot is performed.
So the overall could look like this:
DECLARE #cols AS nvarchar(max)
, #query AS nvarchar(max)
SELECT #cols = STUFF((
SELECT DISTINCT
',' + QUOTENAME(YEAR([date]))
FROM [dbo].[Tickets]
FOR xml PATH (''), TYPE
)
.value('.', 'NVARCHAR(MAX)')
, 1, 1, '')
SET #query = 'SELECT [Year], [Label], '
+ #cols
+ ' FROM (
SELECT
d.Year
, a.label
, a.value
FROM (
SELECT
YEAR([Date]) AS [Year]
, SUM([Drop]) AS [Drop]
, SUM([TicketsDistributed]) AS [TicketsDistributed]
, SUM([TicketsSold]) AS [TicketsSold]
, SUM([GrossTickets]) AS [GrossTickets]
, SUM([GrossTickets]) / SUM(TicketsSold) AS [PerCap]
FROM [dbo].[Tickets]
GROUP BY
[Year]
) AS d
CROSS APPLY (
VALUES
(1,''Drop'',t.Drop)
, (2,''TicketsDistributed'',t.TicketsDistributed)
, (3,''TicketsSold'',t.TicketsSold)
, (4,''GrossTickets'',t.GrossTickets)
, (5,''PerCap'',t.PerCap)
) AS a (row_order,label,value)
) x
pivot
(
max([x.Value])
for [x.Year] in (' + #cols + ')
) p
ORDER BY [row_order]'
EXECUTE sp_executesql #query;