Combination of dynamic pivot and static pivot in SQL Server - sql

Question

Dynamic pivot combined combined with static aggregates
I have a table that looks something like this:
Place State Category CategCount MCount Buys Cost
London UK Old 3 NULL 22 4.50
London UK Old 6 5 3 22.00
Brussels BE Young 2 NULL 4 3.50
Brussels BE M NULL 5 12 1.20
Brussels BE M NULL 2 1 1.20
I basically need to:
Group by a number of fields (Place, State, Category in the example)
Count per such group
Sum MCount, Cost (and others, not in example) per group, these columns are static
Pivot over Category and sum CategCount for each such grouped category (here Old, Young). This is the dynamic part
Result should look like:
Count Place State Category SumMCount SumOld SumYoung SumCost SumBuys
2 London UK Old 5 9 0 26.50 25
1 Brussels BE Young 0 0 2 3.50 4
2 Brussels BE NULL 7 0 0 2.40 13
I know how to get a dynamic pivot query (as per https://stackoverflow.com/a/38505375/111575) and I know how to do the static part. But I don't know how to combine the two. Anybody any ideas? Maybe I go about it all wrong?
What I've got so far:
The following gives me the proper dynamic pivot results for Old and Young, but not sure how to add the count and the the 'regular' sums/aggregates to it:
create table #temp
(
Place nvarchar(20),
State nvarchar(20),
Category nvarchar(20) null,
CategCount int null,
MCount int null,
Buys int,
Cost int
)
insert into #temp values ('London', 'UK', 'Old', 3, NULL, 22, 4.50)
insert into #temp values ('London', 'UK', 'Old', 6, 5, 3, 22.00)
insert into #temp values ('Brussels', 'BE', 'Young', 2, NULL, 4, 3.50)
insert into #temp values ('Brussels', 'BE', 'M', NULL, 5, 12, 1.20)
insert into #temp values ('Brussels', 'BE', 'M', NULL, 2, 1, 1.20)
DECLARE #cols AS NVARCHAR(MAX)='';
DECLARE #query AS NVARCHAR(MAX)='';
SELECT #cols = #cols + QUOTENAME(Category) + ',' FROM (select distinct Category from #temp where CategCount IS NOT NULL) as tmp
select #cols = substring(#cols, 0, len(#cols)) --trim "," at end
--select (#cols) as bm
set #query =
'SELECT * from
(
select
sum(CategCount) as totalCatCount,
Category
from #temp
group by Category
) src
pivot
(
max(totalCatCount) for Category in (' + #cols + ')
) piv'
execute(#query)
drop table #temp
Returning:
And the following is the 'regular' query without the pivoting:
select count(*) as count, place, state, category,
sum(ISNULL(CategCount, 0)) as SumCatCount,
sum(ISNULL(MCount, 0)) as SumMCount,
sum(ISNULL(buys, 0)) as SumBuys,
sum(Cost) as SumCost
from #temp
group by place, state, category
Returning:
But it should look something like this:

Answer 1

I have used your static pivot part of the query as the source of dynamic pivot. Create two sets of dynamic pivot column list. One for pivoting and the another with Coalesce() to select pivoted columns (to convert null into 0). If there is no categcount for any category then that category has been replaced with null (case when). Two more aliases for Category and SumCatCount have been created since those were used in pivot condition.
Here goes your answer:
create table #temp
(
Place nvarchar(20),
State nvarchar(20),
Category nvarchar(20) null,
CategCount int null,
MCount int null,
Buys int,
Cost int
)
insert into #temp values ('London', 'UK', 'Old', 3, NULL, 22, 4.50)
insert into #temp values ('London', 'UK', 'Old', 6, 5, 3, 22.00)
insert into #temp values ('Brussels', 'BE', 'Young', 2, NULL, 4, 3.50)
insert into #temp values ('Brussels', 'BE', 'M', NULL, 5, 12, 1.20)
insert into #temp values ('Brussels', 'BE', 'M', NULL, 2, 1, 1.20)
DECLARE #cols AS NVARCHAR(MAX)='';
DECLARE #query AS NVARCHAR(MAX)='';
DECLARE #colsForSelect AS NVARCHAR(MAX)='';
SET #cols = STUFF((SELECT distinct ',' + quotename(category)
FROM #temp where CategCount is not null
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
SET #colsForSelect = STUFF((SELECT distinct ',' + ' Coalesce('+quotename(category)+',0) '+ quotename(category)
FROM #temp where CategCount is not null
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
--select (#cols) as bm
set #query =
'SELECT count,place,state,(case when OldSumCatCount >0 then OldCategory else null end)Category,SumMCount, ' + #colsForSelect + ',SumCost,SumBuys from
(
select count(*) as count, place, state,category OldCategory, category,
sum(ISNULL(MCount, 0)) as SumMCount,
sum(ISNULL(CategCount, 0)) as OldSumCatCount,
sum(ISNULL(CategCount, 0)) as SumCatCount,
sum(Cost) as SumCost,
sum(ISNULL(buys, 0)) as SumBuys
from #temp
group by place , state, category
) src
pivot
(
max(SumCatCount) for Category in (' + #cols + ')
) piv
order by place desc,count'
execute(#query)
GO
count
place
state
Category
SumMCount
Old
Young
SumCost
SumBuys
2
London
UK
Old
5
9
0
26
25
1
Brussels
BE
Young
0
0
2
3
4
2
Brussels
BE
null
7
0
0
2
13
db<>fiddle here

Answer 2

Thanks to #Larnu in the comments for pointing me in the right direction. His/her statement on "you cannot JOIN a static to a dynamic query" and that either all or nothing has to be dynamic, prompted me to build onto the dynamic part and simply extend it.
I thought I needed to repeat the columns somehow in the PIVOT section, but that appears to not be the case. Only the column you want to pivot, apparently (logically so, once you think about it).
The only part I haven't figured out yet is how to get rid of NULL in the resulting set, hopefully someone answers with that in mind ;).
DECLARE #cols AS NVARCHAR(MAX)='';
DECLARE #query AS NVARCHAR(MAX)='';
SELECT #cols = #cols + QUOTENAME(Category) + ',' FROM (select distinct Category from #temp where CategCount IS NOT NULL) as tmp
select #cols = substring(#cols, 0, len(#cols)) --trim "," at end
--select (#cols) as bm
set #query =
'SELECT * from
(
select
count(*) as count,
Place,
State,
Category,
Category as CatPivot,
sum(ISNULL(CategCount, 0)) as TotalCatCount,
sum(ISNULL(Buys, 0)) as SumBuys,
sum(ISNULL(Cost, 0)) as SumCost,
sum(ISNULL(MCount, 0)) as SumMCount
from #temp
group by Category, Place, State
) src
pivot
(
max(TotalCatCount) for CatPivot in (' + #cols + ')
) piv'
execute(#query)

Answer 3

Here I am sharing another answer which is same but as suggested by #Anthony Hancock dynamic column names for pivot have been created with string_agg() instead of stuff() and xml path for(). It's way too faster and more readable (for SQL Server 2017 and onward)
DECLARE #cols AS NVARCHAR(MAX)='';
DECLARE #query AS NVARCHAR(MAX)='';
DECLARE #colsForSelect AS NVARCHAR(MAX)='';
select #cols =string_agg(category,',') from (
select distinct category FROM #temp where CategCount is not null )t
select #colsForSelect= STRING_AGG(category,',') from
(select distinct 'coalesce('+category+',0) '+category category FROM #temp where CategCount is not null )t
set #query =
'SELECT count,place,state,(case when OldSumCatCount >0 then OldCategory else null end)Category,SumMCount, ' + #colsForSelect + ',SumCost,SumBuys from
(
select count(*) as count, place, state,category OldCategory, category,
sum(ISNULL(MCount, 0)) as SumMCount,
sum(ISNULL(CategCount, 0)) as OldSumCatCount,
sum(ISNULL(CategCount, 0)) as SumCatCount,
sum(Cost) as SumCost,
sum(ISNULL(buys, 0)) as SumBuys
from #temp
group by place , state, category
) src
pivot
(
max(SumCatCount) for Category in (' + #cols + ')
) piv
order by place desc,count'
execute(#query)