CREATE TABLE tryout (pid NUMBER, cname CLOB, ppos CLOB, decision CLOB)
CREATE TABLE player (pid NUMBER, pname CLOB, ycard CLOB, hs NUMBER)
CREATE TABLE college (cname CLOB, state CLOB, enr NUMBER)

What are the unique types of player positions in the tryout?
SELECT COUNT(DISTINCT ppos) FROM tryout
SELECT COUNT(DISTINCT "ppos") FROM "tryout"