How to find if an observation or ID is in multiple table ?

[bersys02]

Hello,

I am trying to find out how many ID's/observations/persons are in different tables or variables ? For instance, if I want to find how the number of people who has multiple nationalities or more than 1. How can I code this ?

Thank you. 

[tarheel13]

Post some data if you can. Hard to help you without seeing it.

[andreas_lds]

Hardly possible to suggest something useful without more information. So please post example data in usable form (a data step using datalines).

[Ksharp]

proc sql;
select id from a
intersect
select id from b
intersect
select id from c
............
;
quit;