Håkon Wullum

CoreSQL.md

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+# Core 
+
+``` sql
+CREATE TABLE films (id SERIAL PRIMARY KEY, title VARCHAR(255), genre VARCHAR(255), realeseYear INTEGER, score INTEGER, UNIQUE (title))
+
+ALTER TABLE films RENAME COLUMN realeseyear TO releaseYear
+
+INSERT INTO films (title, genre, releaseyear, score) VALUES ('The Shawshank Redemption', 'Drama', 1994, 9), ('The Godfather', 'Crime', 1972, 9), ('The Dark Knight', 'Action', 2008, 9), ('Alien', 'SciFi', 1979, 9), ('Total Recall', 'SciFi', 1990, 8), ('The Matrix', 'SciFi', 1999, 8), ('The Matrix Resurrections', 'SciFi', 2021, 5), ('The Matrix Reloaded', 'SciFi', 2003, 6), ('The Hunt for Red October', 'Thriller', 1990, 7), ('Misery', 'Thriller', 1990, 7), ('The Power Of The Dog', 'Western', 2021, 6), ('Hell or High Water', 'Western', 2016, 8), ('The Good the Bad and the Ugly', 'Western', 1966, 9), ('Unforgiven', 'Western', 1992, 7)
+
+SELECT * FROM films
+
+SELECT * FROM films ORDER BY score DESC
+SELECT * FROM films ORDER BY score ASC
+
+SELECT * FROM films WHERE score > 7
+SELECT * FROM films WHERE score < 8
+
+SELECT * FROM films WHERE releaseyear = 1990
+SELECT * FROM films WHERE releaseyear < 2000
+SELECT * FROM films WHERE releaseyear > 1990
+SELECT * FROM films WHERE releaseyear < 2000 AND releaseyear > 1989
+
+SELECT * FROM films WHERE genre = 'SciFi'
+SELECT * FROM films WHERE genre = 'Western' AND releaseyear < 2000
+
+SELECT * FROM films WHERE title LIKE '%Matrix%';
+```
+
+# Extentions
+## 1
+``` sql
+SELECT AVG(score) FROM films 
+SELECT COUNT(title) FROM films 
+SELECT genre, AVG(score) FROM films GROUP BY genre 
+```
+## 2
+``` sql
+CREATE TABLE directors (id SERIAL PRIMARY KEY, name VARCHAR(255))
+INSERT INTO directors (name) VALUES ('Quentin Tarantino'), ('Martin Scorsese'), ('Tim Burton'), ('Steven Spielberg')
+
+ALTER TABLE films ADD COLUMN directorsId INTEGER
+ALTER TABLE films ADD CONSTRAINT directorFK FOREIGN KEY (directorsId) REFERENCES directors(directorsId)
+
+UPDATE films SET directorsid = 1 WHERE releaseyear < 1999 AND releaseyear > 1980
+UPDATE films SET directorsid = 1 WHERE releaseyear > 1999 
+UPDATE films SET directorsid = 3 WHERE score < 8
+UPDATE films SET directorsid = 2 WHERE releaseyear = 1999
+
+SELECT films.title, directors.name FROM films JOIN directors ON films.directorsid = directors.directorsid
+```
+## 3
+``` sql
+SELECT directors.name, COUNT(films.title) FROM directors JOIN films ON films.directorsid = directors.directorsid GROUP BY directors.name
+```