get rank of players' height in plpgsql - postgresql

Question

We are going to have the rank of height, but I got 0 for all players
I convert the feet and inches into cm first, and use the sample code teacher gave us.
Here is my code:
CREATE OR REPLACE FUNCTION player_height_rank (firstname VARCHAR, lastname VARCHAR) RETURNS int AS $$
DECLARE
rank INTEGER:= 0;
offset INTEGER:= 0;
tempValue FLOAT:= NULL;
r record;
BEGIN
FOR r IN SELECT ((p.h_feet * 30.48) + (p.h_inches * 2.54)) AS height， p.firstname, p.lastname
FROM players p
ORDER BY ((p.h_feet * 30.48) + (p.h_inches * 2.54)) DESC, p.firstname, p.lastname
LOOP
IF r.height = tempValue then
offset := offset + 1;
ELSE
rank := rank + offset + 1;
offset := 0;
tempValue := r.height;
END IF;
IF r.firstname = $1 AND r.lastname = $2 THEN
RETURN rank;
END IF;
END LOOP;
-- not in DB
RETURN 0;
END;
$$ LANGUAGE plpgsql;
--select * from player_height_rank('Ming', 'Yao');

Answer 1

Your function works fine for me if I correct two bugs:
One of your commas is not really a comma, but a “fullwidth comma”, UNICODE code point FF0C, which causes a syntax error.
You have a variable name offset, which causes SQL syntax errors because it is a reserved key word in SQL. If you really need to use that name, you have to enclose it in double quotes (") throughout, but it is better to choose a different name.
The reason this causes a problem is that an assignment like offset := offset + 1; in PL/pgSQL is translated into an SQL statement like SELECT offset + 1 INTO offset;.
You can do the whole thing in a single SQL query, which is more efficient:
SELECT rank
FROM (SELECT firstname,
lastname,
rank() OVER (ORDER BY h_feet + 12 * h_inches)
FROM players
) dummy
WHERE firstname = 'Ming'
AND lastname = 'Yao';