loesungen als html Kommentar

- [**00**] - Zeigen Sie **alle Spalten** und **alle Zeilen** aus der Tabelle `customer`.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        *

    FROM customer

    ;

    -->

    ```sql-output

    +-------------+----------+------------+-----------+-------------------------------------+------------+--------+---------------------+---------------------+

    | customer_id | store_id | first_name | last_name | email                               | address_id | active | create_date         | last_update         |

- [**01**] - Zeigen Sie nur die Spalten `first_name`, `last_name` und `email` aus der Tabelle `customer`.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        first_name,

        last_name,

        email

    FROM customer

    ;

    -->

    ```sql-output

    +------------+-----------+-------------------------------------+

    | first_name | last_name | email                               |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        first_name AS Vorname,

        last_name AS Nachname,

        email

    FROM customer

    ;

    -->

    ```sql-output

    +----------+----------+-------------------------------------+

    | Vorname  | Nachname | email                               |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        first_name AS Vorname,

        last_name AS Nachname,

        email

    FROM customer

    LIMIT 5

    ;

    -->

    ```sql-output

    +-----------+----------+-------------------------------------+

    | Vorname   | Nachname | email                               |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        first_name

    FROM actor

    ORDER BY first_name

    ;

    -->

    ```sql-output

    +-------------+

    | first_name  |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT DISTINCT

        first_name

    FROM actor

    ORDER BY first_name

    ;

    -->

    ```sql-output

    +-------------+

    | first_name  |

- [**06**] - Finden Sie alle Filme (Tabelle `film`) mit Länge (length) > 150 Minuten. Zeigen Sie nur die Spalten `title` und `length`.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        title AS Titel,

        length AS Länge

    FROM film

    WHERE length > 150

    ;

    -->

    ```sql-output

    +-------------------------+--------+

    | Titel                   | Länge  |

- [**07**] - Finden Sie alle Filme, deren Mietdauer (rental_duration) genau 5 Tage beträgt. Zeigen Sie nur die Spalten `title` und `rental_duration`.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        title AS Filmtitel,

        rental_duration AS Mietdauer

    FROM film

    WHERE rental_duration = 5

    ;

    -->

    ```sql-output

    +-------------------------+-----------+

    | Filmtitel               | Mietdauer |

- [**08**] - Finden Sie alle Filme mit Mietpreis (rental_rate) <= 2.99 **und** Mietdauer von genau 6 Tagen. Zeigen Sie nur die Spalten `title`, `rental_rate` und `rental_duration`.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        title AS Filmtitel,

        rental_rate AS Mietpreis,

        rental_duration AS Mietdauer

    FROM film

    WHERE rental_rate <= 2.99

        AND rental_duration = 6

    ;

    -->

    ```sql-output

    +-------------------------+-----------+-----------+

    | Filmtitel               | Mietpreis | Mietdauer |

- [**09**] - Welche Schauspieler haben den Vornamen 'Tom'?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        actor_id,

        first_name,

        last_name

    FROM actor

    WHERE first_name = "Tom"

    ;

    -->

    ```sql-output

    +----------+------------+-----------+

    | actor_id | first_name | last_name |

- [**10**] - Welche Schauspieler haben den Nachnamen 'Johansson'?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        actor_id,

        first_name,

        last_name

    FROM actor

    WHERE last_name = "Johansson"

    ;

    -->

    ```sql-output

    +----------+------------+-----------+

    | actor_id | first_name | last_name |

- [**11**] - Welche Schauspieler haben einen Nachnamen, der an der 2. Stelle ein 'i' hat?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        actor_id,

        first_name,

        last_name

    FROM actor

    WHERE last_name LIKE "_i%"

    ;

    -->

    ```sql-output

    +----------+------------+-------------+

    | actor_id | first_name | last_name   |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        actor_id,

        first_name,

        last_name

    FROM actor

    WHERE first_name LIKE "A%a"

    ;

    -->

    ```sql-output

    +----------+------------+-------------+

    | actor_id | first_name | last_name   |

- [**13**] - Welche Schauspieler haben einen Nachnamen, der genau 5 Zeichen lang ist?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        actor_id,

        first_name,

        last_name

    FROM actor

    WHERE last_name LIKE "_____"

    # WHERE LENGTH(last_name) = 5

    ;

    -->

    ```sql-output

    +----------+-------------+-----------+

    | actor_id | first_name  | last_name |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        actor_id,

        first_name,

        last_name,

        LENGTH(last_name) AS Länge

    FROM actor

    WHERE LENGTH(last_name) = LENGTH(first_name)

    ;

    -->

    ```sql-output

    +----------+------------+-----------+--------+

    | actor_id | first_name | last_name | Länge  |

- [**15**] - Finden Sie alle Filme, deren Beschreibung (film.description) den Teilstring "**database**" enthält.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        film_id,

        title,

        description

    FROM film

    WHERE description LIKE "%database%"

    ;

    -->

    ```sql-output

    +---------+---------------------+------------------------------------------------------------------------------------------------------------------------------------+

    | film_id | title               | description                                                                                                                        |

- [**16**] - Wie viele Filme sind in der Datenbank gespeichert?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        COUNT(*) AS num_films

    FROM film

    ;

    -->

    ```sql-output

    +-----------+

    | num_films |

- [**17**] - Wie viele Schauspieler gibt es insgesamt?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        COUNT(*) AS num_actors

    FROM actor

    ;

    -->

    ```sql-output

    +------------+

    | num_actors |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        COUNT(DISTINCT last_name) AS distinct_actor_names

    FROM actor

    ;

    -->

    ```sql-output

    +----------------------+

    | distinct_actor_names |

- [**19**] - Wie viele verschiedene Filmbewertungen (film.rating) gibt es?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        COUNT(DISTINCT rating) AS distinct_film_ratings

    FROM film

    ;

    -->

    ```sql-output

    +------------------------+

    | disctinct_film_ratings |

- [**20**] - Wie ist die durchschnittliche Laufzeit (film.length) aller Filme?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        AVG(length) AS avg_film_length

    FROM film

    ;

    -->

    ```sql-output

    +-----------------+

    | avg_film_length |

- [**21**] - Finden Sie den kleinsten Mietpreis (film.rental_rate) aller Filme.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        MIN(rental_rate) AS min_rental_rate

    FROM film

    ;

    -->

    ```sql-output

    +-----------------+

    | min_rental_rate |

- [**22**] - Finden Sie die maximale Mietdauer (film.rental_duration) aller Filme.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        MAX(rental_duration) AS max_rental_days

    FROM film

    ;

    -->

    ```sql-output

    +-----------------+

    | max_rental_days |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        COUNT(*) AS num_payments

    FROM payment

    ;

    -->

    ```sql-output

    +--------------+

    | num_payments |

- [**24**] - Summieren Sie die Beträge (payment.amount) aller Zahlungen.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        SUM(amount) AS sum_payments

    FROM payment

    ;

    -->

    ```sql-output

    +--------------+

    | sum_payments |

- [**25**] - Finden Sie den kleinsten, größten und den durchschnittlichen Betrag (payment.amount) aller Zahlungen.

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        MIN(amount) AS min,

        MAX(amount) AS max,

        AVG(amount) AS avg

    FROM payment

    ;

    -->

    ```sql-output

    +------+-------+----------+

    | min  | max   | avg      |

- [**26**] - Wie viele Filme gibt es pro Altersfreigabe (film.rating)?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        rating,

        COUNT(*) AS film_count

    FROM film

    GROUP BY rating

    ;

    -->

    ```sql-output

    +--------+------------+

    | rating | film_count |

    {% endhint %}

    <hr>

- [**27**] - Wie hoch ist die durchschnittliche Mietdauer (film.rental_duration) pro Altersfreigabe (film.rating)?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        rating,

        AVG(rental_duration) AS avg_rental_duration

    FROM film

    GROUP BY rating

    ;

    -->

    ```sql-output

    +--------+---------------------+

    | rating | avg_rental_duration |

    {% endhint %}

    <hr>

- [**28**] - Wie ist die durchschnittliche Laufzeit (film.length) der Filme, gruppiert nach Altersfreigabe (film.rating)?

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        rating,

        AVG(length) AS avg_length

    FROM film

    GROUP BY rating

    ORDER BY avg_length

    ;

    -->

    ```sql-output

    +--------+------------+

    | rating | avg_length |

- [**29**] - Finden Sie den kleinsten, größten und den durchschnittlichen Betrag (payment.amount) aller Zahlungen **pro** Kunde (payment.customer_id).

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        customer_id,

        MIN(amount) AS min,

        MAX(amount) AS max,

        AVG(amount) AS avg

    FROM payment

    GROUP BY customer_id

    ;

    -->

    ```sql-output

    +-------------+------+-------+----------+

    | customer_id | min  | max   | avg      |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        rating,

        COUNT(*) AS film_count

    FROM film

    GROUP BY rating

    ORDER BY film_count DESC

    LIMIT 1

    ;

    -->

    ```sql-output

    +--------+------------+

    | rating | film_count |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name,

        a.address,

        a.district,

        a.postal_code,

        ct.city,

        ctr.country

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

    ORDER BY c.customer_id

    ;

    -->

    ```sql-output

    +-------------+-------------+--------------+-------------------------------------+----------------------+-------------+-----------------+-----------------+

    | customer_id | first_name  | last_name    | address                             | district             | postal_code | city            | country         |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name,

        ctr.country

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

    WHERE ctr.country LIKE "Germany"

    ORDER BY c.customer_id

    ;

    -->

    ```sql-output

    +-------------+------------+------------+---------+

    | customer_id | first_name | last_name  | country |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        a.actor_id,

        a.first_name,

        a.last_name

    FROM actor a

        JOIN film_actor fa ON fa.actor_id = a.actor_id

        JOIN film f ON f.film_id = fa.film_id

    WHERE title LIKE "Academy Dinosaur"

    ;

    -->

    ```sql-output

    +----------+------------+-----------+

    | actor_id | first_name | last_name |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name

    FROM film f

        JOIN inventory i ON i.film_id = f.film_id

        JOIN rental r ON r.inventory_id = i.inventory_id

        JOIN customer c ON c.customer_id = r.customer_id

    WHERE f.title LIKE "Academy Dinosaur"

    ORDER BY c.customer_id

    ;

    -->

    ```sql-output

    +-------------+------------+-------------+

    | customer_id | first_name | last_name   |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        ctr.country_id,

        ctr.country,

        COUNT(*) AS num_cities

    FROM city c

        JOIN country ctr ON ctr.country_id = c.country_id

    GROUP BY ctr.country_id

    ;

    -->

    ```sql-output

    +------------+---------------------------------------+------------+

    | country_id | country                               | num_cities |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        a.actor_id,

        a.first_name,

        a.last_name,

        COUNT(*) AS film_count

    FROM actor a

        JOIN film_actor fa ON fa.actor_id = a.actor_id

    GROUP BY a.actor_id

    ;

    -->

    ```sql-output

    +----------+-------------+--------------+------------+

    | actor_id | first_name  | last_name    | film_count |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.name AS Film_Kategorie,

        COUNT(*) AS Anzahl_Filme

    FROM film_category fc

        JOIN category c ON fc.category_id = c.category_id

    GROUP BY fc.category_id

    ORDER BY Anzahl_Filme DESC

    ;

    -->

    ```sql-output

    +----------------+--------------+

    | Film_Kategorie | Anzahl_Filme |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        cat.category_id,

        cat.`name`,

        COUNT(*) AS num_rentals

    FROM rental r

        JOIN inventory i ON i.inventory_id = r.inventory_id

        JOIN film_category fc ON fc.film_id = i.film_id

        JOIN category cat ON cat.category_id = fc.category_id

    GROUP BY cat.category_id, cat.`name`

    ORDER BY num_rentals DESC

    LIMIT 3

    ;

    -->

    ```sql-output

    +-------------+-----------+-------------+

    | category_id | name      | num_rentals |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        cat.category_id,

        cat.`name`,

        COUNT(*) AS num_rentals

    FROM rental r

        JOIN inventory i ON i.inventory_id = r.inventory_id

        JOIN film_category fc ON fc.film_id = i.film_id

        JOIN category cat ON cat.category_id = fc.category_id

    GROUP BY cat.category_id, cat.`name`

    ORDER BY num_rentals ASC

    LIMIT 3

    ;

    -->

    ```sql-output

    +-------------+--------+-------------+

    | category_id | name   | num_rentals |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name,

        COUNT(*) AS num_rentals

    FROM rental r

        JOIN customer c ON c.customer_id = r.customer_id

    GROUP BY

        c.customer_id,

        c.first_name,

        c.last_name

    HAVING num_rentals > 30

    ORDER BY num_rentals DESC

    ;

    -->

    ```sql-output

    +-------------+-------------+--------------+-------------+

    | customer_id | first_name  | last_name    | num_rentals |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name,

        COUNT(*) AS Ausgeliehene_Filme

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

        JOIN rental r ON r.customer_id = c.customer_id

    WHERE ctr.country LIKE "Germany"

    GROUP BY c.customer_id

    ORDER BY c.customer_id

    ;

    -->

    ```sql-output

    +-------------+------------+------------+--------------------+

    | customer_id | first_name | last_name  | Ausgeliehene_Filme |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name,

        SUM(amount) AS Ausleih_Gebühren

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

        JOIN payment p ON p.customer_id = c.customer_id

    WHERE ctr.country LIKE "Germany"

    GROUP BY c.customer_id

    ORDER BY c.customer_id

    ;

    -->

    ```sql-output

    +-------------+------------+------------+-------------------+

    | customer_id | first_name | last_name  | Ausleih_Gebühren  |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        ca.name AS Kategorie,

        COUNT(*) AS Häufigkeit

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

        JOIN rental r ON r.customer_id = c.customer_id

        JOIN inventory i ON i.inventory_id = r.inventory_id

        JOIN film_category fc ON fc.film_id = i.film_id

        JOIN category ca ON ca.category_id = fc.category_id

    WHERE ctr.country LIKE "Germany"

    GROUP BY ca.name

    ORDER BY Häufigkeit DESC

    LIMIT 1

    ;

    -->

    ```sql-output

    +-----------+-------------+

    | Kategorie | Häufigkeit  |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        c.customer_id,

        c.first_name,

        c.last_name,

        SUM(amount) AS bisher_bezahlt

    FROM customer c

        JOIN payment p ON p.customer_id = c.customer_id

    GROUP BY c.customer_id

    ORDER BY bisher_bezahlt DESC

    LIMIT 3

    ;

    -->

    ```sql-output

    +-------------+------------+-----------+----------------+

    | customer_id | first_name | last_name | bisher_bezahlt |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT DISTINCT

        f.film_id,

	    f.title

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

        JOIN rental r ON r.customer_id = c.customer_id

        JOIN inventory i ON i.inventory_id = r.inventory_id

        JOIN film f ON f.film_id = i.film_id

    WHERE ctr.country LIKE "Germany"

    ORDER BY f.film_id

    ;

    -->

    ```sql-output

    +---------+-------------------------+

    | film_id | title                   |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        ctr.country AS Land,

        COUNT(*) AS Anzahl_Kunden

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

    GROUP BY Land

    ORDER BY Anzahl_Kunden DESC

    ;

    -->

    ```sql-output

    +---------------------------------------+---------------+

    | Land                                  | Anzahl_Kunden |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        ctr.country AS Land,

        COUNT(*) AS Anzahl_Kunden

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

    GROUP BY Land

    HAVING Anzahl_Kunden > 9

    ORDER BY Anzahl_Kunden DESC

    ;

    -->

    ```sql-output

    +--------------------+---------------+

    | Land               | Anzahl_Kunden |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        ctr.country_id,

        ctr.country

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        JOIN city ct ON ct.city_id = a.city_id

        RIGHT JOIN country ctr ON ctr.country_id = ct.country_id

    WHERE c.customer_id IS NULL

    ;

    -->

    ```sql-output

    +------------+-----------+

    | country_id | country   |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        ct.city_id,

        ct.city,

        ctr.country

    FROM customer c

        JOIN address a ON a.address_id = c.address_id

        RIGHT JOIN city ct ON ct.city_id = a.city_id

        JOIN country ctr ON ctr.country_id = ct.country_id

    WHERE c.customer_id IS NULL

    ;

    -->

    ```sql-output

    +---------+------------+-----------+

    | city_id | city       | country   |

    {% endhint %}

    {% hint "Ergebnis", "success" %}

    <!--

    SELECT

        customer_id,

        first_name,

        last_name

    FROM customer

    WHERE customer_id NOT IN (

        SELECT DISTINCT

            c.customer_id

        FROM rental r

            JOIN inventory i ON i.inventory_id = r.inventory_id

            JOIN film_category fc ON fc.film_id = i.film_id

            JOIN category cat ON cat.category_id = fc.category_id

            JOIN customer c ON c.customer_id = r.customer_id

        WHERE cat.`name` = "Horror"

    )

    ;

    -->

    ```sql-output

    +-------------+-------------+-------------+

    | customer_id | first_name  | last_name   |