How to return a unique record
Solution 1:
You can inner join to a table with max creation_date per secondaryid to ensure you have only latest creation_date
SELECT DISTINCT *
FROM PRIMARY
JOIN SECONDARY ON PRIMARY.SECONDARYID = SECONDARY.ID
inner join (
select
secondaryid
, max(creationdate) maxdate
from PRIMARY
group by secondaryid) mx
on PRIMARY.seconardyid = mx.secondaryid and mx.maxdate = PRIMARY.creationdate
WHERE PRIMARY.CREATIONDATE BETWEEN (NOW() - INTERVAL 14 DAY) AND NOW()