CREATE TABLE endowment (donator_name VARCHAR, school_id VARCHAR)
CREATE TABLE school (school_id VARCHAR, school_name VARCHAR)

How many donors have endowment for school named 'Glenn'?
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"
SELECT COUNT(DISTINCT "T1"."donator_name") FROM "endowment" AS "T1" JOIN "school" AS "T2" ON "Glenn" = "T2"."school_name" AND "T1"."school_id" = "T2"."school_id"