Solved Lab

Lab_solved.sql

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+USE sakila
+
+-- You need to use SQL built-in functions to gain insights relating to the duration of movies:
+-- 1.1 Determine the shortest and longest movie durations and name the values as max_duration and min_duration.
+SELECT MIN(length) AS min_duration,
+MAX(length) AS max_duration
+FROM sakila.film;
+
+-- 1.2. Express the average movie duration in hours and minutes. Don't use decimals.
+-- Hint: Look for floor and round functions.
+  SELECT FLOOR(AVG(length)) AS minutes,
+      FLOOR(AVG(length)/60) AS hours
+  FROM sakila.film;
+
+  SELECT FLOOR(AVG(length)/60) AS hours, FLOOR(AVG(length) % 60) AS minutes FROM sakila.film;
+
+
+-- You need to gain insights related to rental dates:
+-- 2.1 Calculate the number of days that the company has been operating.
+-- Hint: To do this, use the rental table, and the DATEDIFF() function to subtract the earliest date in the rental_date column from the latest date-- .
+SELECT DATEDIFF(MAX(return_date), MIN(rental_date)) AS days_of_operations
+FROM sakila.rental;
+
+-- 2.2 Retrieve rental information and add two additional columns to show the month and weekday of the rental. Return 20 rows of results.
+SELECT 
+DATE_FORMAT(rental_date,'%M') AS month,
+DAYNAME(rental_date) AS weekday
+FROM sakila.rental
+LIMIT 20;
+
+--  2.3 Bonus: Retrieve rental information and add an additional column called DAY_TYPE with values 'weekend' or 'workday', depending on the day of the week.
+-- Hint: use a conditional expression.
+SELECT 
+CASE WHEN DAYNAME(rental_date) IN ('Saturday', 'Sunday') 
+THEN 'weekend' 
+ELSE 'workday' 
+END AS DAY_TYPE 
+FROM sakila.rental;
+
+
+-- 3 You need to ensure that customers can easily access information about the movie collection. To achieve this, retrieve the film titles and their rental duration. If any rental duration value is NULL, replace it with the string 'Not Available'. Sort the results of the film title in ascending order.
+-- Please note that even if there are currently no null values in the rental duration column, the query should still be written to handle such cases in the future.
+-- Hint: Look for the IFNULL() functionYou need to ensure that customers can easily access information about the movie collection. To achieve this, retrieve the film titles and their rental duration. If any rental duration value is NULL, replace it with the string 'Not Available'. Sort the results of the film title in ascending order.
+SELECT
+title,
+IFNULL(rental_duration, 'Not Available')
+FROM sakila.film
+ORDER BY title ASC;
+
+
+-- Next, you need to analyze the films in the collection to gain some more insights. Using the film table, determine:
+-- 1.1 The total number of films that have been released.
+SELECT
+COUNT(release_year)
+FROM sakila.film
+
+-- 1.2 The number of films for each rating.
+SELECT renting, COUNT(*) AS total_films
+FROM sakila.film
+GROUP BY rating;
+
+-- 1.3 The number of films for each rating, sorting the results in descending order of the number of films. This will help you to better understand the popularity of different film ratings and adjust purchasing decisions accordingly.
+SELECT rating, COUNT(*) AS total_films
+ FROM sakila.film 
+ GROUP BY rating 
+ ORDER BY total_films DESC;
+
+-- Using the film table, determine:
+SELECT rating, 
+ROUND(AVG(length), 2) AS mean_duration 
+FROM sakila.film 
+GROUP BY rating 
+ORDER BY mean_duration DESC;
+
+
+-- 2.2 Identify which ratings have a mean duration of over two hours in order to help select films for customers who prefer longer movies.
+SELECT rating,
+       ROUND(AVG(length), 2) AS avg_duration
+FROM sakila.film
+GROUP BY rating
+HAVING AVG(length) > 120;
+
+-- 3 Bonus: determine which last names are not repeated in the table actor.
+SELECT DISTINCT (last_name)
+FROM sakila.actor
+GROUP BY last_name
+HAVING COUNT(*) = 1;
+
+