Hello, how are you!  Can you provide me with a list of all of the email addresses in this database?
select email_address from people
Perfect!  Can you update the list to include all of the candidate IDs in addition to these email addresses?
select t2.candidate_id,t1.email_address from people as t1 join candidates as t2 on t1.person_id = t2.candidate_id
Can you filter this list to show only the row that contains the email address of stanley.monahan@example.org?
select t2.candidate_id, t1.email_address from people as t1 join candidates as t2 on t1.person_id = t2.candidate_id where t1.email_address = 'stanley.monahan@example.org'