Conditional calculation in SQL Server - sql-server

Question

friends:
I'm now have a problem about conditional calculation in SQL Server.
I have set some data from SQL Server as an example in excel like this:
No Employee Month Commission1 Commission2
1 A Jan 10 5
2 A Jan 10 4
3 B Jan 15 3
4 B Jan 15 4
5 C Jan 10 3
6 C Jan 10 4
7 D Jan 13 3
8 D Jan 13 4
9 DM Jan 0 6
10 DM Jan 0 8
11 A Feb 15 4
12 A Feb 15 5
13 B Feb 20 5
14 B Feb 20 4
15 C Feb 9 3
16 C Feb 9 4
17 D Feb 14 5
18 D Feb 14 6
19 DM Feb 0 13
20 DM Feb 0 10
And the result I want is like this:
Employee Jan No# Feb No#
A 20 2 30 2
B 30 2 40 2
C 20 2 18 2
D 26 2 28 2
DM 44 10 59 10
For every sales,Employee A,B,C,D only have commission1 as payment,the commission2 is for DM. So , in Jan , DM's commission is SUM(E2:E9)
I can do it easy in excel , but how can I do this in sql server?
I make my try code like this:
select [Month],Employee,SUM(Commission1) Commission,count(distinct([No])) No#
from table1
WHERE Employee IN ('A','B','C','D')
group by [Month],Employee
union
select 'DM' as Employee,[Month],SUM(Commission2) Commission,count(distinct([No])) No#
from table1
WHERE Employee IN ('A','B','C','D','DM')
group by [Month],Employee
And I get the result
Employee Month Commission No#
A Jan 20 2
B Jan 30 2
C Jan 20 2
D Jan 26 2
DM Jan 44 10
A Feb 30 2
B Feb 40 2
C Feb 18 2
D Feb 28 2
DM Feb 59 10
The result format is not what I want.I tried pivot after this query,but failed,it seems I only can pivot one state?
Another question: If I want the month growth automatic (In actual data , there's not only Jan and Feb) in the result ,not write [Jan],[Feb],[Mar]... in pivot code, how to do it?
Who can help me?
Thanks!

Answer 1

Here is a PIVOT solution:
Test data:
DECLARE #t table(Employee varchar(2), Month char(3), Commission1 int, Commission2 int)
INSERT #t values
('A','Jan',10,5 ),('A','Jan',10,4),('B','Jan',15,3),
('B','Jan',15,4 ),('C','Jan',10,3),('C','Jan',10,4),
('D','Jan',13,3 ),('D','Jan',13,4),('DM','Jan',0,6),
('DM','Jan',0,8 ),('A','Feb',15,4),('A','Feb',15,5),
('B','Feb',20,5 ),('B','Feb',20,4),('C','Feb',9,3),
('C','Feb',9,4 ),('D','Feb',14,5),('D','Feb',14,6),
('DM','Feb',0,13),('DM','Feb',0,10)
Query:
;WITH CTE as
(
SELECT
Employee, Month,
CASE WHEN Employee = 'DM' THEN
SUM(Commission2) over (partition by [Month])
ELSE Commission1 END com,
CASE WHEN Employee = 'DM'
THEN row_number() over
(PARTITION BY Employee, [Month] ORDER BY (SELECT 1)) ELSE 1 END rn
FROM #t
)
SELECT Employee, [Jan], [Feb], [Mar] -- add more months
FROM
CTE
PIVOT
(SUM(com)
FOR [Month] IN ([Jan], [Feb], [Mar])) AS pvt -- add more months
WHERE rn = 1
Result:
Employee Jan Feb Mar
A 20 30 NULL
B 30 40 NULL
C 20 18 NULL
D 26 28 NULL
DM 44 59 NULL

Answer 2

In SqlServer you can do so using PIVOT operator as like below:
Please refer PIVOT syntax
select tmp.employee,pv.[jan] as Jan_Commission, pv.[feb] as Feb_Commission from
(
select employee,month,commission1 from table_name
)tmp
pivot (
sum(commission1)
for [month] in ([jan],[feb])
)pv;