CREATE TABLE tryout (cName VARCHAR2, pPos VARCHAR2)
CREATE TABLE college (state VARCHAR2, cName VARCHAR2)

How many states that have some college students playing in the mid position but not in the goalie position.
SELECT COUNT(*) FROM (SELECT T1.state FROM college AS T1 JOIN tryout AS T2 ON T1.cName = T2.cName WHERE T2.pPos = 'mid' EXCEPT SELECT T1.state FROM college AS T1 JOIN tryout AS T2 ON T1.cName = T2.cName WHERE T2.pPos = 'goalie')
WITH "cte" AS (SELECT "T1"."state" FROM "college" "T1" JOIN "tryout" "T2" ON "T1"."cName" = "T2"."cName" AND "T2"."pPos" = 'mid' EXCEPT SELECT "T1"."state" FROM "college" "T1" JOIN "tryout" "T2" ON "T1"."cName" = "T2"."cName" AND "T2"."pPos" = 'goalie') SELECT COUNT(*) FROM "cte" "cte"