Searching for % or _ in a title

Question

i was running the following queries
select title from table where title like '%_%';
select title from table where title like '%%%';
and for some reason the result was the whole table.
How can i search for a title that contains either an underscore or a percentage in it whithout returning the whole table?
are these oracle special characters that we can't use?

Answer 1

Two options. If you are on 10g or above you can use regexp_like otherwise use the escape key word:
where txt_column like '%\%%' escape '\'  -- The choice of escape
   or txt_column like '%|_%' escape '|'  -- character is arbitrary
where regexp_like(text_column,'.*%.*') -- match %
   or regexp_like(text_column,'.*_.*') -- match _
   or regexp_like(text_column,'.*[%_].*') -- match both % or _
   or regexp_like(text_column,'.*[.*].*') -- match period . or *