Question

Assuming the proper tables are in place – what is the difference between the two queries – when would they return different results

select *
from quiz_user qu
join quiz_topic qt on qu.quiz_id = qt.quiz_id and qt.topic_id=44
where qu.user_id=9

select *
from quiz_user qu
join quiz_topic qt on qu.quiz_id = qt.quiz_id 
where qu.user_id=9
and qt.topic_id=44

Thanks

Answer 1

I don’t see any difference in queries as they are. However, if you used LEFT JOIN instead of INNER (default), results would be different.