Posted by Amy, Feb. 23, 2023, 12:50 p.m.
#52 why there could be film_id that is not in film_actor table?
I was assuming all film_id in film table should have a list of their casts under film_actor table, but that seems not the case. I am trying to understand why this could happen.
My testing query is:
select film.film_id
from film
left join film_actor
on film.film_id=film_actor.film_id
where film_actor.film_id is null
Return results:
| film_id |
|---|
| 257 |
| 323 |
| 803 |
