SQL count of intersections with total field - mysql

Question

For example we have this ServiceRequests source table in database:
| Id | ClientDepartment | ServiceType | DateTimeServiced |
|----|------------------|-------------|------------------|
| 1 | Sales | Networking | 15.01.17 |
| 2 | Development | Networking | 14.02.17 |
| 3 | Development | Networking | 09.04.17 |
| 4 | Sales | Software | 11.03.17 |
| 5 | Sales | Hardware | 30.03.17 |
| 6 | Development | Hardware | 15.04.17 |
Need to make SQL select query and get result:
|Client\Service| Networking | Software | Hardware | Total |
|--------------|------------|----------|----------|-------|
| Sales | 1 | 1 | 1 | 3 |
| Development | 2 | 0 | 1 | 3 |
Where numbers are count of intersections between ServiceType and ClientDepartment (services per department).
Trying something like this gives very wrong result:
select ClientDepartment,
(select count(t1.ClientDepartment)
from ServiceRequests t1
where t1.ServiceType = 'Networking'
) as Networking,
(select count(t1.ClientDepartment)
from ServiceRequests t1
where t1.ServiceType = 'Software'
) as Software,
(select count(t1.ClientDepartment)
from ServiceRequests t1
where t1.ServiceType = 'Hardware'
) as Hardware,
(select count(t1.ClientDepartment)
from ServiceRequests t1
) as Total
from ServiceRequests
group by ClientDepartment
|Client\Service| Networking | Software | Hardware | Total |
|--------------|------------|----------|----------|-------|
| Sales | 3 | 1 | 2 | 6 |
| Development | 3 | 1 | 2 | 6 |
Hope for help, create example table code

Answer 1

You could use sum on CASE WHEN and group by
in this way you dn't need subselect for each count
select
ClientDepartment
, sum(case when ServiceType = 'Networking' then 1 else 0 end )as Networking
, sum(case when ServiceType = 'Software' then 1 else 0 end ) as Software
, sum(case when ServiceType = 'Hardware' then 1 else 0 end ) as Hardware
, sum(case when ServiceType = 'Networking' then 1 else 0 end ) +
sum(case when ServiceType = 'Software' then 1 else 0 end ) +
sum(case when ServiceType = 'Hardware' then 1 else 0 end ) as Total
from ServiceRequests
group by ClientDepartment
this should work for both the DB ..

Answer 2

We Can Achieve Desired result using Dynamic Sql
IF OBJECT_ID('Tempdb..#Temp') IS NOT NULL
DROP TABLE #Temp
;With cte( Id , ClientDepartment , ServiceType , DateTimeServiced )
AS
(
SELECT 1 , 'Sales' , 'Networking' , '15.01.17' Union all
SELECT 2 , 'Development' , 'Networking' , '14.02.17' Union all
SELECT 3 , 'Development' , 'Networking' , '09.04.17' Union all
SELECT 4 , 'Sales' , 'Software' , '11.03.17' Union all
SELECT 5 , 'Sales' , 'Hardware' , '30.03.17' Union all
SELECT 6 , 'Development' , 'Hardware' , '15.04.17'
)
SELECT ClientDepartment,
ServiceType,
COUNT(ServiceType)OVER(Partition by ClientDepartment,ServiceType Order by Id) AS Cnt INTO #Temp FROM cte --Sample data created here
DECLARE #Column1 nvarchar(max),
#Sql nvarchar(max),
#Column2 nvarchar(max)
SELECT #Column1=STUFF((SELECT DISTINCT ', '+ 'ISNULL('+ServiceType +',''0'') AS '+ServiceType FROM #Temp
FOR XML PATH ('')),1,1,'')
SELECT #Column2=STUFF((SELECT DISTINCT ', '+ +QUOTENAME(ServiceType) FROM #Temp
FOR XML PATH ('')),1,1,'')
SET #Sql='
SELECT *,'+REPLACE(#Column2,',','+')+' AS Total FROM
(
SELECT ClientDepartment AS ''Client\Service'','+#Column1 +' FROM
(
SELECT * FROm #Temp
)AS SRc
PIVOT
(
MAX(Cnt) FOR ServiceType IN ('+#Column2+')
)AS PVT
)DT
Order by 1 desc
'
PRINT #Sql
EXEC(#Sql)
OutPut
Client\Service Hardware Networking Software Total
---------------------------------------------------------
Sales 1 1 1 3
Development 1 2 0 3