text: -- Select all records of movie rentals from customer with ID 115
  SELECT *
  FROM renting
  WHERE r.customer_id = 115;
  
  
  SELECT *
  FROM renting
  WHERE rating IS NOT NULL -- Exclude those with null ratings
  AND customer_id = 115;
  
  
  SELECT *
  FROM renting
  WHERE rating IS NOT NULL -- Exclude null ratings
  AND customer_id = 1; -- Select all ratings from customer with ID 1
  
  
  SELECT *
  FROM customers AS c -- Select all customers with at least one rating
  WHERE EXISTS 
  	(SELECT *
  	FROM renting AS r
  	WHERE rating IS NOT NULL 
  	AND r.customer_id = c.customer_id);
  
  
  SELECT *  -- Select the records of all actors who play in a Comedy
  FROM actsin AS ai
  LEFT JOIN movies AS m
  ON ai.movie_id = m.movie_id
  WHERE m.genre = 'Comedy';
  
  
  SELECT *
  FROM actsin AS ai
  LEFT JOIN movies AS m
  ON m.movie_id = ai.movie_id
  WHERE m.genre = 'Comedy'
  AND ai.actor_id = 1; -- Select only the actor with ID 1
  
  
  SELECT *
  FROM actors AS a
  WHERE EXISTS
  	(SELECT *
  	 FROM actsin AS ai
  	 LEFT JOIN movies AS m
  	 ON m.movie_id = ai.movie_id
  	 WHERE m.genre = 'Comedy'
  	 AND ai.actor_id = a.actor_id);
  
  
  SELECT a.nationality, COUNT(*) -- Report the nationality and the number of actors for each nationality
  FROM actors AS a
  WHERE EXISTS
  	(SELECT ai.actor_id
  	 FROM actsin AS ai
  	 LEFT JOIN movies AS m
  	 ON m.movie_id = ai.movie_id
  	 WHERE m.genre = 'Comedy'
  	 AND ai.actor_id = a.actor_id)
  GROUP BY a.nationality;
  