Find id of the candidate whose email is stanley.monahan@example.org?
create table candidates (candidate_id varchar, PRIMARY KEY (candidate_id)); create table people (person_id varchar, email_address varchar, PRIMARY KEY (person_id))
select t2.candidate_id from people as t1 join candidates as t2 on t1.person_id = t2.candidate_id where t1.email_address = "stanley.monahan@example.org"