Identifizieren der Lieblingsdarstellenden von Kundengruppen

Datengestützte Entscheidungsfindung in SQL

Irene Ortner

Data Scientist at Applied Statistics

SQL-Anweisungen in einer Abfrage kombinieren

LEFT JOIN
WHERE
GROUP BY
HAVING
ORDER BY

Nötige Infos: Ausleihen, Darstellende, Kundschaft

Unsere Frage: Wer ist sind die beliebtesten Darstellenden einer Kundengruppe?

Verknüpfen der Tabelle renting mit den Tabellen

customers
actsin
actors

SELECT *
FROM renting as r
LEFT JOIN customers AS c
ON r.customer_id = c.customer_id
LEFT JOIN actsin as ai
ON r.movie_id = ai.movie_id
LEFT JOIN actors as a
ON ai.actor_id = a.actor_id;

Männliche Kundschaft

Darstellende in Filmen, die oft von männlichem Publikum angeschaut werden

SELECT a.name, 
       COUNT(*)
FROM renting as r
LEFT JOIN customers AS c
ON r.customer_id = c.customer_id
LEFT JOIN actsin as ai
ON r.movie_id = ai.movie_id
LEFT JOIN actors as a
ON ai.actor_id = a.actor_id

WHERE c.gender = 'male'
GROUP BY a.name;

Wer ist Lieblingsschauspielerin/-schauspieler?

Darstellende, die am häufigsten angeschaut werden
Filme mit bester Durchschnittsbewertung, wenn angeschaut

SELECT a.name, 
       COUNT(*) AS number_views, 
       AVG(r.rating) AS avg_rating
FROM renting as r
LEFT JOIN customers AS c
ON r.customer_id = c.customer_id
LEFT JOIN actsin as ai
ON r.movie_id = ai.movie_id
LEFT JOIN actors as a
ON ai.actor_id = a.actor_id

WHERE c.gender = 'male'
GROUP BY a.name;

HAVING und ORDER BY hinzufügen

SELECT a.name, 
       COUNT(*) AS number_views, 
       AVG(r.rating) AS avg_rating
FROM renting as r
LEFT JOIN customers AS c
ON r.customer_id = c.customer_id
LEFT JOIN actsin as ai
ON r.movie_id = ai.movie_id
LEFT JOIN actors as a
ON ai.actor_id = a.actor_id

WHERE c.gender = 'male'
GROUP BY a.name
HAVING AVG(r.rating) IS NOT NULL
ORDER BY avg_rating DESC, number_views DESC;

HAVING und ORDER BY hinzufügen

| name               | number_views | avg_rating |
|--------------------|--------------|------------|
| Ray Romano         | 3            | 10.00      |
| Sean Bean          | 2            | 10.00      |
| Leonardo DiCaprio  | 3            | 9.33       |
| Christoph Waltz    | 3            | 9.33       |

Lass uns üben!

Datengestützte Entscheidungsfindung in SQL