azreel_iv_answers.sql

-- KENA BELANJA TONY ROMA'S NI HMMMMH 🤔 (AKU DAH SACRIFICE ALMOST HALF HOUR UTK KAU)

-- 1. Find the titles of all movies directed by Steven Spielberg.

SELECT title
FROM Movie
WHERE director = 'Steven Spielberg';

-- 2. Find all years that have a movie that received a rating of 4 or 5, and sort them in increasing order

SELECT DISTINCT year
FROM Movie
INNER JOIN Rating ON Movie.mID = Rating.mID
WHERE stars IN (4, 5)
ORDER BY year;

-- 3. Find the titles of all movies that have no ratings

SELECT title
FROM Movie
WHERE mID NOT IN (SELECT mID FROM Rating);

-- 4. For each movie that has at least one rating, find the highest number of stars that movie received. Return the movie title and number of stars. Sort by movie title. 

SELECT title, MAX(stars)
FROM Movie
INNER JOIN Rating USING(mID)
GROUP BY mID
ORDER BY title;


-- 5. For each movie that has at least one rating, find the movie title and total number of stars, the highest star and the person who gave highest star.

SELECT title,
SUM(stars) AS total_stars,
MAX(stars) AS highest_stars,
name AS highest_stars_reviewer
FROM Movie
INNER JOIN Rating USING(mID)
INNER JOIN Reviewer USING(rID)
WHERE Movie.mID = Rating.mID
AND Rating.rID = Reviewer.rID
GROUP BY mID;

-- 6. For all cases where the same reviewer rated the same movie twice and gave it a higher rating the second time, return the reviewer's name and the title of the movie.

SELECT name, title
FROM Movie
INNER JOIN Rating R1 USING(mID)
INNER JOIN Rating R2 USING(rID, mID)
INNER JOIN Reviewer USING(rID)
WHERE R1.ratingDate < R2.ratingDate AND R1.stars < R2.stars;

-- 7. For each movie, return the title and the 'rating spread', that is, the difference between highest and lowest ratings given to that movie. Sort by rating spread from highest to lowest, then by movie title.

SELECT title, (MAX(stars) - MIN(stars)) AS rating_spread
FROM Movie
INNER JOIN Rating USING(mID)
GROUP BY mID
ORDER BY rating_spread DESC, title;

-- 8. Find the names of reviewers for every director (one row per director with all reviewers)

SUSAHHHHHHH!!!!!!!!!! OK AIR TAK PAYAH BELANJA! TONY ROMA'S!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!