Oracle sql return true if exists question

Question

How do I check if a particular element exists in a table - how can I return true or false?

I have a table that has

• user_id
• user_password

Answer 1

Or you could do this:

select decode(max(USER_ID), null, 'FALSE', 'TRUE') BOOL_VAL
from USER_TABLE where USER_ID = [some USER_ID here]