Gunakan hasil pilih dan bandingkan

Dua kemungkinan solusi:

1. Gunakan subkueri
2. Gunakan variabel

Solusi subkueri

select a, a>2 as b
from (select 1 as a) as q;

Solusi 'variabel'

set @a = 1;
select @a as a, @a>2 as b;