CREATE TABLE school (school_id TEXT, school_name TEXT, location TEXT, mascot TEXT, enrollment DECIMAL, ihsaa_class TEXT, ihsaa_football_class TEXT, county TEXT)
CREATE TABLE endowment (endowment_id DECIMAL, school_id DECIMAL, donator_name TEXT, amount DECIMAL)
CREATE TABLE budget (school_id DECIMAL, year DECIMAL, budgeted DECIMAL, total_budget_percent_budgeted DECIMAL, invested DECIMAL, total_budget_percent_invested DECIMAL, budget_invested_percent TEXT)

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"