SQL Server is there a way around repeated conditional lines - sql

Question

Hello I am trying to clean up a query and there is one line that is repeated six times.
Is there a way to set something like a constant in SQL?
Here is an example of the issue:
select Distinct DSF.CityName,
( Select count (Distinct DSF1.IncdtKey)
from dbo.IncidentFile DSF1
Where DSF1.IncidentMostSevere in ('1', '2', '4', '5', '6')
and DSF1.CategoryKey in ('15', '01', '02', '03', '04', '05', '06')<-----
and DSF1.CityName = DSF.CityName) as 'Weapons Possession 11-12',
( Select count (Distinct DSF2.IncdtKey)
from dbo.IncidentFile DSF2
Where DSF2.IncidentMostSevere in ('7', '8', '9', '10', '11', '12')
and DSF2.CategoryKey in ('15', '01', '02', '03', '04', '05', '06') <-----
and DSF2.CityName = DSF.CityName) as 'Drugs Related 11-12',
( Select count (Distinct DSF3.IncdtKey)
from dbo.IncidentFile DSF3
Where DSF3.IncidentMostSevere in ('14', '15', '17', '20', '21', '22', '26')
and DSF3.CategoryKey in ('15', '01', '02', '03', '04', '05', '06') <-----
and DSF3.CityName = DSF.CityName) as 'Incident with Injury 11-12',
( Select count (Distinct DSF4.IncdtKey)
from dbo.IncidentFile DSF4
Where DSF4.IncidentMostSevere in ('16', '18', '19', '23', '24', '25')
and DSF4.CategoryKey in ('15', '01', '02', '03', '04', '05', '06') <-----
and DSF4.CityName = DSF.CityName) as 'Incident no Injury 11-12',
( Select count (Distinct DSF5.IncdtKey)
from dbo.IncidentFile DSF5
Where DSF5.IncidentMostSevere in ('3', '13', '29', '31', '32', '33')
and DSF5.CategoryKey in ('15', '01', '02', '03', '04', '05', '06') <-----
and DSF5.CityName = DSF.CityName) as 'Other reason for 11-12',
( Select count (Distinct DSF6.IncdtKey)
from dbo.IncidentFile DSF6
Where DSF6.CategoryKey in ('15', '01', '02', '03', '04', '05', '06') <-----
and DSF6.CityName = DSF.CityName) as 'Total Incidents'
from dbo.IncidentFile DSF
group by DSF.CityName
Order by DSF.CityName
Thanks

Answer 1

You should be able to use a CTE and then an aggregate function with CASE expression:
;with cte as
(
select distinct CityName,
IncidentMostSevere,
IncdtKey
from dbo.IncidentFile
where CategoryKey in ('15', '01', '02', '03', '04', '05', '06')
)
select CityName,
count(case
when IncidentMostSevere in ('1', '2', '4', '5', '6')
then IncdtKey end) as 'Weapons Possession 11-12',
count(case
when IncidentMostSevere in ('7', '8', '9', '10', '11', '12')
then IncdtKey end) as 'Drugs Related 11-12',
count(case
when IncidentMostSevere in ('14', '15', '17', '20', '21', '22', '26')
then IncdtKey end) as 'Incident with Injury 11-12',
count(case
when IncidentMostSevere in ('16', '18', '19', '23', '24', '25')
then IncdtKey end) as 'Incident no Injury 11-12',
count(case
when IncidentMostSevere in ('3', '13', '29', '31', '32', '33')
then IncdtKey end) as 'Other reason for 11-12',
count(case
when IncidentMostSevere in ('15', '01', '02', '03', '04', '05', '06')
then IncdtKey end) as 'Total Incidents'
from cte
group by CityName
order by CityName

Answer 2

This approach works by moving your sub queries into the from clause and adding the list of categories once in your where clause.
select
DSF.CityName,
Dsf1.cnt as 'Weapons Possession 11-12',
Dsf2.cnt as 'Drugs Related 11-12',
...
Dfsn.cnt as 'Total Incidents'
From
dbo.IncidentFile DSF
Inner join
(
Select
DSF.CategoryKey,
DSF.CityName,
count (Distinct DSF.IncdtKey) as cnt
from
dbo.IncidentFile DSF
Where
DSF.IncidentMostSevere in ('1', '2', '4', '5', '6').
group by
1, 2
) DSF1
On DSF1.CityName = DSF.CityName
Inner join
(
Select
DSF.CategoryKey,
DSF.CityName,
count (Distinct DSF.IncdtKey) as cnt
from
dbo.IncidentFile DSF
Where
DSF.IncidentMostSevere in ('7', '8', '9', '10', '11', '12')
group by
1, 2
) DSF2
On DSF2.CityName = DSF.CityName
...
Inner join
(
Select
DSF.CategoryKey,
DSF.CityName,
count (Distinct DSF.IncdtKey) as cnt
from
dbo.IncidentFile DSF
Where
DSF.IncidentMostSevere in ('7', '8', '9', '10', '11', '12')
group by
1, 2
) DSFn
On dfsn.CityName = DSF.CityName
Where
dfsn.CategoryKey in ('15','01','02,'03','04','05','06')
Order by DSF.CityName