Check if a row exists or not in postgresql

Question

I have seen many posts about this in SO. But I could not get an answer. I want to the query to check if a particular row exists or not in a table. If it exists, it should return me a string true and stop the search there itself and if not return false.

Answer 1

select
  case when exists (select true from table_name where table_column=?)
    then 'true'
    else 'false'
  end;

But it would be better to just return boolean instead of string:

select exists (select true from table_name where table_column=?);