Return Value from sql commands

Question

I am currently using the SQL command

Select * from where name='john'

Is it possible to return 20 no matter the query, for example

Select * from where name='john' or return = 20

Answer 1

EDIT If you have an oracle database you can do something like that:

SELECT * 
FROM dual
WHERE 1=0
UNION
SELECT '20'
FROM dual;