What are the names of the schools with some players in the mid position but no goalies?
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'}]