How many donors have endowment for school named "Glenn"?
create table school (school_id varchar, school_name varchar, PRIMARY KEY (school_id)); create table endowment (donator_name varchar, school_id varchar, PRIMARY KEY (donator_name))
select count(distinct t1.donator_name) from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = "glenn"