while studying about the As statment i get to knwon it is executed at the end of the uqery so if in case i am trying to use the alisd name i have created in a query like

select film as movie from films where movie = "3 Idiots"

then it is giving me error and thats expected as “AS” statment is just execeuted at the time of ouput but if the same thing i do for a sub query for an example

select title, first_name, last_name from film INNER JOIN (select first_name,last_name,film_id from actor INNEr JOIN film_actor ON actor.actor_id = film_actor.actor_id) As actor_info ON film.film_id = actor_info.film_id Where actor_info.first_name = 'Nick' ANDwalker actor_info.last_name = 'Wahlberg';

then it is working fine , so can anyone help me understand this concept

then it is working fine , so can anyone help me understand this concept