Solved lab

Data_agg-transformation.sql

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+-- 1.1 Determine the **shortest and longest movie durations** and name the values as `max_duration` and `min_duration`.
+SELECT * FROM sakila.film;
+
+SELECT title, length AS min_duration
+FROM sakila.film
+WHERE length = (SELECT MIN(length) FROM sakila.film);
+
+SELECT title, length AS max_duration
+FROM sakila.film
+WHERE length = (SELECT MAX(length) FROM sakila.film);
+
+-- 1.2. Express the **average movie duration in hours and minutes**. Don't use decimals.
+SELECT
+FLOOR(AVG(length) / 60) AS hours,
+FLOOR(MOD(AVG(length), 60)) AS minutes
+FROM sakila.film;
+
+-- 2.1 Calculate the **number of days that the company has been operating**.
+SELECT 
+    DATEDIFF(MAX(rental_date), MIN(rental_date)) AS operating_days
+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 
+    rental_id,
+    rental_date,
+    MONTHNAME(rental_date) AS rental_month,
+    DAYNAME(rental_date) AS rental_weekday,
+    inventory_id,
+    customer_id,
+    return_date,
+    staff_id
+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.*
+
+SELECT 
+    rental_id,
+    rental_date,
+    MONTHNAME(rental_date) AS rental_month,
+    DAYNAME(rental_date) AS rental_weekday,
+    CASE 
+        WHEN DAYOFWEEK(rental_date) IN (1,7) THEN 'weekend'  -- 1 = Sunday, 7 = Saturday
+        ELSE 'workday'
+    END AS DAY_TYPE,
+    inventory_id,
+    customer_id,
+    return_date,
+    staff_id
+FROM sakila.rental
+LIMIT 20;
+
+-- 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.
+SELECT 
+    title,
+    IFNULL(length, 'Not Available') AS rental_duration
+FROM sakila.film
+ORDER BY title ASC;
+
+-- 4. You need to retrieve the **concatenated first and last names of customers**, along with the 
+-- **first 3 characters of their email** address, so that you can address them by their first name 
+-- and use their email address to send personalized recommendations. The results should be ordered
+-- by last name in ascending order to make it easier to use the data.*
+
+SELECT 
+    CONCAT(first_name, ' ', last_name) AS full_name,
+    LEFT(email, 3) AS email_prefix
+FROM sakila.customer
+ORDER BY last_name ASC;
+
+-- Challenge 2
+-- 1.1 The **total number of films** that have been released.
+SELECT COUNT(*) AS total_films
+FROM sakila.film;
+
+-- 1.2 The **number of films for each rating**.
+SELECT rating, COUNT(*) AS films_per_rating
+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.
+SELECT rating, COUNT(*) AS films_per_rating
+FROM sakila.film
+GROUP BY rating
+ORDER BY films_per_rating DESC;
+
+-- 2.1 The **mean film duration for each rating**, and sort the results in descending order of the mean duration. Round off the average lengths to two decimal places. This will help identify popular movie lengths for each category.
+SELECT 
+    rating, 
+    ROUND(AVG(length), 2) AS avg_duration
+FROM sakila.film
+GROUP BY rating
+ORDER BY avg_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 last_name
+FROM sakila.actor
+GROUP BY last_name
+HAVING COUNT(*) = 1;
+
+
+
+
+

README.md

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-![logo_ironhack_blue 7](https://user-images.githubusercontent.com/23629340/40541063-a07a0a8a-601a-11e8-91b5-2f13e4e6b441.png)
+r![logo_ironhack_blue 7](https://user-images.githubusercontent.com/23629340/40541063-a07a0a8a-601a-11e8-91b5-2f13e4e6b441.png)
 
 # Lab | SQL Data Aggregation and Transformation