find the names of states that have some collage plating in goalie and mid positions.
SELECT T1.state FROM college AS T1 JOIN tryout AS T2 ON T1.cName   =   T2.cName WHERE T2.pPos   =   'goalie' INTERSECT SELECT T1.state FROM college AS T1 JOIN tryout AS T2 ON T1.cName   =   T2.cName WHERE T2.pPos   =   'mid'
states with colleges having players in both goalie and mid positions requires an INTERSECT operation between two selects; colleges playing in specific positions refers to joining college and tryout tables on college name and filtering by player position (pPos);