Question: What are the names of the states that have some college students playing in the mid position but not the goalie position?
SQL: 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'