INNER vs LEFT JOIN

join.sql

# Good: INNER JOIN

...
SELECT a.email AS email, a.created_at AS expressed_interest_at 
FROM helpscout.conversation AS a
INNER JOIN helpscout.conversation AS b ON a.id = b.conversation_id
WHERE b.conversation_id = 'beacon-interest'
...

# Okay: LEFT JOIN

...
select 
    c.email,
    c.created_at as expressed_interest_at
from hubspot.conversation c
left join hubspot.conversation_tag t on c.id = t.conversation_id
where t.tag = 'beacon-interest'
...