You can create a table with all combinations of the ID's using SQL. This is called a Cartesian product and is generally flagged as a possible programming error. That's because it is a common mistake that can easily create a run-away query because often the number of combinations gets very large. Assuming you have a workable number of combinations (the product of the number of unique ID values for each of your three ID variables), this is would be the way:
proc sql;
create table all_ids as
select a.id as id_a, b.id as id_b, c.id as id_c
compged(a.id, b.id) as comp_ab, compged(a.id, c.id) as com_ac, compged(b.id, c.id) as comp_bc
from a,b,c;
quit;
You can then work out your best choices for each id by doing some magic on the resulting table.
As the query is a join without join criteria you will get the following note in your log. But in this case it is intentional and you can ignore it:
NOTE: The execution of this query involves performing one or
more Cartesian product joins that can not be optimized.
Hope this helps,
- Jan.
... View more
