Question: What are the distinct types of mills that are built by American or Canadian architects?
Schema: create table architect (id varchar, PRIMARY KEY (id)); create table mill (type varchar, architect_id varchar, PRIMARY KEY (type))
SQL: select distinct t1.type from mill as t1 join architect as t2 on t1.architect_id = t2.id where t2.nationality = 'american' or t2.nationality = 'canadian'