SQL - Select Help - Case When? Return Value from Second Table?

Question

Hi - next to folks on this board I am probably somewhere between a Beginner and an Intermediate SQL user.
Ive been using a case when statement in plsql to find "all those who's status in any program was cancelled during a specific time, but have become or are still active in a second program"
So, Im effectively trying to return a value from a second table in a case when, but its not liking anthing other than a declared text like 'Yes' or 'No'.
Here is the select statement - is there another way to do this where I can get the results I need?
case when pp.party_id in (select pp1.party_id  -- Cancelled clients Active in another program
                                   from asa.program_participation          pp1,
                                        asa.curr_prog_participation_status cpps1
                                  where pp1.program_participation_id = cpps1.program_participation_id
                                    and pp1.party_id = pp.party_id
                                    and cpps1.code_value = 'ACT')
            then 'Yes' else 'No' end  as Active_in_Other_Prg
So - in place of 'Yes' i basically want the program that they are active in or pp1.program_id, else Null
It is possible that the client can be active in more than one program as well.
Any assistance is greatly appreciated, i explored with if's and decodes but I cant get anything to work.
Batesey

Answer 1

Sounds like an outer join. See ora doc: Joins
select p.*
,      q.party_id
,      q.program_id
from   table_with_party_id p
,    ( select pp1.party_id  -- Cancelled clients Active in another program
       ,      pp1.program_id
       from   asa.program_participation          pp1,
              asa.curr_prog_participation_status cpps1
       where  pp1.program_participation_id = cpps1.program_participation_id
       and    pp1.party_id = pp.party_id
       and    cpps1.code_value = 'ACT') q
where p.party_id = q.party_id ( +)
Note: In the example above there shoudn't be a space between the ( and +), but the forum software automagically converts this to
The outer join will link show all records from the p table and only records from q if the party_id matches, ie q.party_id and q.program_id  will be null if there is no match.
edit: added program_id