workspace Theory for SQL

SELECT*
FROM cinema.reviews
Limit 5

--Take two tabels as input and return all from both tabels
SELECT id
FROM cinema.reviews
UNION
SELECT id
from cinema.roles;

-- Select id, film_id and filter by film_id then union with roles table after that filter by id
SELECT id,  film_id
FROM cinema.reviews
WHERE film_id > 74
UNION
SELECT id, film_id
FROM cinema.roles
WHERE id <> 10;

-- UNION ALL include duplcates
SELECT film_id, actor_id, last_update
FROM dvdrentals.film_actor
UNION ALL
SELECT film_id, category_id, last_update
FROM dvdrentals.film_category
ORDER BY film_id
LIMIT 5;

-- Choose all records from two table UNION ALL
SELECT *
FROM dvdrentals.category
UNION ALL
SELECT *
FROM dvdrentals.country
ORDER BY last_update
LIMIT 5;

-- INTERSECT not fount in this two table
SELECT id, title
FROM cinema.films
INTERSECT
SELECT id, name
FROM cinema.people
ORDER by id

--We see where this table INTERSECT
select id, film_id
from cinema.reviews 
intersect
select id, person_id
from cinema.roles

SELECT code, gross_savings
FROM world.economies2010
EXCEPT
SELECT code, gross_savings
FROM world.economies2015
ORDER By code
LIMIT 5;