PLpgSQL function not returning matching titles - postgresql

Question

I am trying to return the movie name and the number of cast and crew when given a text. When I input the string and am using ilike, my query returns no matching titles. I created a view previously that has the movie titles and the number of crew to be input in the function.
My code is:
create or replace view movies_crew as
select movies.id, movies.title, principals.role
from movies
join principals on principals.movie_id=movies.id
where principals.role <> 'producer'
;
create or replace view movie_makers as
select movies_crew.title, count(movies_crew.title) as ncrew
from movies_crew
where movies_crew.title = 'Fight Club'
group by movies_crew.title;
CREATE or REPLACE function Q11(partial_title text)
RETURNS SETOF text
AS $$
DECLARE
title text;
BEGIN
for title in
select movie_makers.title, movie_makers.ncrew
from movie_makers
where movie_makers.title ilike '%$1%'
loop
return next movie_makers.title||'has'||movie_makers.ncrew||'cast and crew';
end loop;
if(not found) then
return next 'No matching titles';
end if;
END;
$$ LANGUAGE plpgsql;
select * from q11('Fight Club')
My database is: https://drive.google.com/file/d/1NVRLiYBVbKuiazynx9Egav7c4_VHFEzP/view?usp=sharing

Answer 1

Your immediate quoting issue aside (has been addressed properly by Jeff), the function can be much simpler and faster like this:
CREATE or REPLACE FUNCTION q11(partial_title text)
RETURNS SETOF text
LANGUAGE plpgsql AS
$func$
BEGIN
RETURN QUERY
SELECT m.title || ' has ' || m.ncrew || ' cast and crew'
FROM movie_makers m
WHERE m.title ~* $1;
IF NOT FOUND THEN
RETURN NEXT 'No matching titles';
END IF;
END
$func$;
Major points:
Your function was still broken. References to movie_makers.title and movie_makers.ncrew wouldn't work that way. I fixed it.
Use RETURN QUERY instead of the loop. This way we also do not need to use or even declare any variables at all. See:
How to return result of a SELECT inside a function in PostgreSQL?
Optionally use the case insensitive regular expression match operator ~*. (Simpler, not faster.)
Difference between LIKE and ~ in Postgres
Either way, you may want to escape special characters. See:
Escape function for regular expression or LIKE patterns
Aside: hardly makes sense to filter on a view that already selects 'Fight Club' as its only row. For a meaningful search, you wouldn't use these views ...

Answer 2

ilike '%$1%'
$1 is not interpolated when inside single quotes, so you are searching for the literal characters $ and 1.
You could instead do:
ilike '%'||$1||'%'