CREATE TABLE school (school_id VARCHAR(255), school_name VARCHAR(255)); CREATE TABLE endowment (donator_name VARCHAR(255), school_id VARCHAR(255))
How many donors have endowment for school named "Glenn"?
    
SQL: 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"