Subtraction between two sql queries

Question

I have 2 queries in MS SQL that return a number of results using the COUNT function.

I can run the the first query and get the first result and then run the other on

Answer 1

I know this is an old post but here is another solution that fit best to my needs (tested on firebird)

SELECT c1-c2 from (select count(*) c1 from t1), (SELECT COUNT(*) c2 from t2);