Lab-mysql-select

mysql_select.sql

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+USE sakila;
+
+-- How many distinct (different) actors' last names are there?
+SELECT COUNT(DISTINCT(last_name)) FROM actor; -- 121 different actors' last name
+
+-- In how many different languages where the films originally produced?
+SELECT COUNT(DISTINCT(language_id)) FROM film; -- Only 1 language
+
+-- How many movies were released with "PG-13" rating?
+SELECT COUNT(rating) FROM film
+	WHERE rating = "PG-13"; -- 223 movies rated PG-13
+
+-- Get 10 the longest movies from 2006.
+SELECT title FROM film
+WHERE release_year = 2006
+ORDER BY length DESC
+LIMIT 10; -- Darn Forrester, Pond Seattle, Chicago North, Muscle Bright, Worst Banger, Gangs Pride,
+		  -- Soldiers evolution, Home pity, Sweet Brotherhood, Control Anthem
+
+-- How many days has been the company operating (check DATEDIFF() function)?
+SELECT DATEDIFF(MAX(rental_date), MIN(rental_date)) FROM rental; -- 266 days
+
+-- Show rental info with additional columns month and weekday. Get 20.
+SELECT *, MONTH(rental_date) AS rental_month, WEEKDAY(rental_date) AS rental_day
+FROM rental
+LIMIT 20;
+	-- 0 = Monday, 1 = Tuesday, 2 = Wednesday, 3 = Thursday, 4 = Friday, 5 = Saturday, 6 = Sunday.
+
+-- Add an additional column day_type with values 'weekend' and 'workday' depending on the rental day of the week.
+SET SQL_SAFE_UPDATES = 0;
+ALTER TABLE rental 
+	ADD day_type CHAR (7);
+UPDATE rental
+SET day_type = "workday"
+WHERE WEEKDAY(rental_date) BETWEEN 0 AND 4;
+UPDATE rental
+SET day_type = "weekend"
+WHERE WEEKDAY(rental_date) BETWEEN 5 AND 6;
+
+-- How many rentals were in the last month of activity?
+SELECT COUNT(*)
+	FROM rental
+	WHERE MONTH(rental_date) = (SELECT MONTH(MAX(rental_date)) FROM rental); -- 182 rental in the last month
+
+-- Get film ratings.
+SELECT DISTINCT(rating) FROM film;
+
+-- Get release years.
+SELECT DISTINCT(release_year) FROM film; -- All were released in 2006
+
+-- Get all films with ARMAGEDDON in the title.
+SELECT * FROM film
+	WHERE title LIKE "%armageddon%";
+
+-- Get all films with APOLLO in the title
+SELECT * FROM film
+	WHERE title LIKE "%apollo%";
+
+-- Get all films which title ends with APOLLO.
+SELECT * FROM film
+	WHERE title LIKE "%apollo";
+
+-- Get all films with word DATE in the title.
+SELECT * FROM film
+	WHERE title LIKE "%date%";
+
+-- Get 10 films with the longest title.
+SELECT * FROM film
+ORDER BY CHAR_LENGTH(title) DESC
+LIMIT 10;
+
+-- Get 10 the longest films.
+SELECT * FROM film
+ORDER BY length DESC
+LIMIT 10;
+
+-- How many films include Behind the Scenes content?
+SELECT COUNT(*) FROM film
+	WHERE special_features LIKE "%Behind the Scenes%"; -- 538 films include Behind the scenes
+
+-- List films ordered by release year and title in alphabetical order.
+SELECT * FROM film
+	ORDER BY release_year, title;
+
+-- Drop column picture from staff.
+ALTER TABLE staff
+	DROP COLUMN picture;
+
+-- A new person is hired to help Jon. Her name is TAMMY SANDERS, and she is a customer.
+SELECT * FROM customer
+WHERE first_name = "Tammy" AND last_name = "Sanders";
+SELECT * FROM staff
+WHERE first_name = "Jon"; -- store_id = 2
+INSERT INTO staff (first_name, last_name, address_id, email, store_id, username)
+VALUES ("Tammy", "Sanders", 79, "tammy.sanders@sakilacustomer.org", 2, "Tammy");
+
+-- Add rental for movie "Academy Dinosaur" by Charlotte Hunter from Mike Hillyer at Store 1. Use current date for the rental_date.
+-- Columns in rental: rental_date, inventory_id, customer_id)
+SELECT * FROM film
+	JOIN inventory
+		ON film.film_id = inventory.film_id
+	WHERE title = "Academy Dinosaur" AND store_id = 1; -- inventory_id of this film in store 1 has 4 different values (1, 2, 3, 4)
+SELECT * FROM customer
+WHERE first_name = 'CHARLOTTE' AND last_name = 'HUNTER'; -- customer_id = 130
+SELECT * FROM staff
+	WHERE store_id = 1; -- in store_id =1, the staff working there is staff_id = 1
+INSERT INTO rental (rental_date, inventory_id, customer_id, staff_id)
+VALUES (curdate(), 1, 130, 1);
+
+-- Delete non-active users, but first, create a backup table deleted_users to store customer_id, email, and the date for the users that would be deleted. Follow these steps:
+	-- 1. Check if there are any non-active users
+    -- 2. Create a table backup table as suggested
+    -- 3. Insert the non active users in the table backup table
+    -- 4. Delete the non active users from the table customer
+SELECT * FROM customer WHERE active = 0;
+SELECT COUNT(*) FROM customer WHERE active = 0; -- There are 15 non-active users
+CREATE TABLE IF NOT EXISTS deleted_users(
+customer_id SMALLINT PRIMARY KEY,
+email VARCHAR(50),
+date DATE
+);
+
+INSERT INTO deleted_users (customer_id, email)
+SELECT customer_id, email FROM customer
+WHERE customer.active = 0;
+UPDATE deleted_users
+SET date = curdate();
+
+SET FOREIGN_KEY_CHECKS=0; 
+DELETE FROM customer WHERE active = 0;
+SET FOREIGN_KEY_CHECKS=1;