Who has donated to "Glenn"?
select t1.donator_name from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = 'Glenn'
Who has donated to "Triton"?
select t1.donator_name from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = 'Triton'
Who has donated to both schools?
select t1.donator_name from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = 'Glenn' intersect select t1.donator_name from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = 'Triton'