231130 sql 시작!

USE sakila;

-- 1.
SELECT category_id, name
FROM category
WHERE name IN ('Comedy', 'Sports', 'Family');

-- 2.
SELECT film_id, category_id
FROM film_category
WHERE film_id = 2;

-- 3.
SELECT category_id, COUNT(category_id)
FROM film_category
GROUP BY category_id;

-- 4.
-- join
SELECT name, COUNT(*) AS film_count
FROM category
         JOIN film_category ON film_category.category_id = category.category_id
WHERE name = 'Comedy'
GROUP BY category.category_id;

-- subquery
SELECT COUNT(*)
FROM film_category
WHERE category_id = (SELECT category_id FROM category WHERE name = 'Comedy');

-- 5.
SELECT name, COUNT(*) AS film_count
FROM category
         JOIN film_category ON film_category.category_id = category.category_id
WHERE name IN ('Comedy', 'Sports', 'Family')
GROUP BY category.category_id;

 

드디어 sql test 시작이다!

처음에는 한동안 쉬운 내용이어서 배우는게 많지 않았는데, 확실히 테스트를 들어오니 배울게 많아져서 좋다!

열심히 보면서 쳐보는중!