Cross-query with IN/INTERSECT, INNER JOIN or EXISTS?

You'll get the same results from all three. I would recommend the INNER JOIN, as it's the simplest to write. The gains in performance will be probably always be negligible, but queries 2 and 3 will require one less index scan. Query 1 will scan cast_info twice.

To update the table after, you can do something like this:

UPDATE PSET P.Person_Name = T.Person_NameFROM Person PINNER JOIN OtherTable T on T.Person_ID = P.Person_ID

And of course, it's always nice to run a SELECT, verify your columns, then change the first two lines to be an update and fire away with confidence.

SELECT P.Person_ID, P.Person_Name, T.Person_ID, T.Person_NameFROM Person PINNER JOIN OtherTable T on T.Person_ID = P.Person_ID

This intersect is redundant

WHERE movie_id IN    (        SELECT movie_id        FROM cast_info        INTERSECT        SELECT movie_id        FROM movie    );

I think the join is the most direct

INSERT INTO person (person_id)SELECT DISTINCT person_idFROM cast_infoINNER JOIN movieON cast_info.movie_id=movie.movie_id;

why?

CREATE TABLE person( id INTEGER PRIMARY KEY AUTOINCREMENT

just use person_id as primary key

and use date for birthday