Combining UNION ALL and ORDER BY in Firebird

Question

This is my first attempt at answering my own question, since someone may well run into this and so it might be of help. Using Firebird, I want to combine the results of two

Answer 1

How about:

select C1, C2, C3 from T1
union all 
select C1, C2, C3 from T2
order by 2

At least in the newer Firebird Versions it works if you order by "Number" instead of using an Alias.