CREATE TABLE club (club_id NUMBER, name CLOB, region CLOB, start_year CLOB)
CREATE TABLE player (player_id NUMBER, name CLOB, position CLOB, club_id NUMBER, apps NUMBER, tries NUMBER, goals CLOB, points NUMBER)
CREATE TABLE club_rank (rank NUMBER, club_id NUMBER, gold NUMBER, silver NUMBER, bronze NUMBER, total NUMBER)
CREATE TABLE competition_result (competition_id NUMBER, club_id_1 NUMBER, club_id_2 NUMBER, score CLOB)
CREATE TABLE competition (competition_id NUMBER, year NUMBER, competition_type CLOB, country CLOB)

What are the maximum and minimum number of silver medals for clubs.
SELECT MAX(silver), MIN(silver) FROM club_rank
SELECT MAX("silver"), MIN("silver") FROM "club_rank"