CREATE TABLE architect (id CLOB, name CLOB, nationality CLOB, gender CLOB)
CREATE TABLE mill (architect_id NUMBER, id NUMBER, location CLOB, name CLOB, type CLOB, built_year NUMBER, notes CLOB)
CREATE TABLE bridge (architect_id NUMBER, id NUMBER, name CLOB, location CLOB, length_meters NUMBER, length_feet NUMBER)

How many architects haven't built a mill before year 1850?
SELECT COUNT(*) FROM architect WHERE NOT id IN (SELECT architect_id FROM mill WHERE built_year < 1850)
SELECT COUNT(*) FROM "architect" WHERE NOT "id" IN (SELECT "architect_id" FROM "mill" WHERE "built_year" < 1850)