Conditional statements within select for strings - sql

Question

at the moment I query my database to find all interactions within a certain date parameter. I also join that table with my InteractionAttendees then join it by TargetGroups table. InteractionAttendees tells me who attended the interaction, TargetGroup tells me about the person, if they are part of a target group such as aboriginal or francophone.
I'm having trouble setting my Aboriginal and Francophone columns. I want to set it to be true if there was any attendees that are in the TargetGroup Table.
select CONVERT(date, getdate()) as ActivityDate,
CASE when Type = 0 Then 'General'
when Type = 1 Then 'Activity'
else 'Task' End as Type,
CASE when Indepth = 0 Then 'False' else 'True' End as Indepth,
Subject,
Comments,
'false' as Aboriginal,
'false' as FrancoPhone,
'false' as Female,
'false' as Youth,
'false' as Other
from Sarnia.dbo.Interactions as X
full outer join sarnia.dbo.InteractionAttendees as Y on X.Id = Y.Interaction_Id
full outer join Sarnia.dbo.TargetGroups as Z on Y.Person_Id = Z.PersonId
where ActivityDate >= '2015-07-01' and ActivityDate <= '2015-09-30'
group by ActivityDate, Type, Indepth, Created, subject, comments
for example
Interaction Table
Id
1
Interaction Attendee Table
Id InteractionId PersonId
1 1 5
2 1 10
TargetGroups Table
Id PersonId TargetValue
1 5 Aboriginal
2 10 Francophone
So my resulted table would be
Activity Date Aboriginal Francophone
---- True True
May I ask how do I properly populate my target group columns.

Answer 1

You can update your query something like this: Pivot in the old fashioned way. Based on your previous questions I am assuming it is a sql server DB.
MAX(IIF(TargetValue = 'Aboriginal', 'True', 'False')) as Aboriginal,
MAX(IIF(TargetValue = 'FrancoPhone', 'True', 'False')) as FrancoPhone
If you have SQL Server 2008 or older you can use something like this
MAX(CASE WHEN TargetValue = 'Aboriginal' THEN 'True' ELSE 'False' END) as Aboriginal,
MAX(CASE WHEN TargetValue = 'FrancoPhone' THEN 'True' ELSE 'False' END) as FrancoPhone

Answer 2

Here is an example of how to do this with a CTE. Note, I added this to the example sql you gave, but that sql has many errors.
with igroup as
(
SELECT IID,
CASE WHEN ACOUNT > 0 THEN true ELSE false END AS Aboriginal,
CASE WHEN FCOUNT > 0 THEN true ELSE false END AS Francophone
FROM (
SELECT InteractionId as IID,
SUM(CASE WHEN TargetValue = 'Aboriginal' THEN 1 ELSE 0 END) as ACOUNT,
SUM(CASE WHEN TargetValue = 'FrancoPhone' THEN 1 ELSE 0 END) as FCOUNT
FROM sarnia.dbo.InteractionAttendees A
LEFT JOIN sarnia.dbo.TargetGroups as G on A.Person_Id = G.PersonId
GROUP BY InteractionId
) X
)
select CONVERT(date, getdate()) as ActivityDate,
CASE when Type = 0 Then 'General'
when Type = 1 Then 'Activity'
else 'Task' End as Type,
CASE when Indepth = 0 Then 'False' else 'True' End as Indepth,
Subject,
Comments,
igroup.Aboriginal,
igroup.FrancoPhone,
from Sarnia.dbo.Interactions as X
full outer join sarnia.dbo.InteractionAttendees as Y on X.Id = Y.Interaction_Id
join igroup on X.Id = igroup.IID
where ActivityDate >= '2015-07-01' and ActivityDate <= '2015-09-30'
group by ActivityDate, Type, Indepth, Created, subject, comments