Find the names of schools that have some players in the mid position but not in the goalie position.
SELECT cName FROM  tryout WHERE pPos  =  'mid' EXCEPT SELECT cName FROM  tryout WHERE pPos  =  'goalie'
SELECT cName FROM  tryout WHERE pPos  =  'mid' EXCEPT SELECT cName FROM  tryout WHERE pPos  =  'goalie'
[{'cName': 'OU'}]