Table schema:
CREATE TABLE school (school_id VARCHAR, school_name VARCHAR); CREATE TABLE endowment (donator_name VARCHAR, school_id VARCHAR)

Question: 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"