SQL練習28：查找描述資訊中包括robot的電影對應的分類名稱以及電影數目

題目鏈接：牛客網

題目描述
查找描述資訊(film.description)中包含robot的電影對應的分類名稱(category.name)以及電影數目(count(film.film_id))，而且還需要該分類包含電影總數量(count(film_category.category_id)) >=5部，

film表

category表

film_category表

CREATE TABLE IF NOT EXISTS film (
film_id smallint(5)  NOT NULL DEFAULT '0',
title varchar(255) NOT NULL,
description text,
PRIMARY KEY (film_id));

CREATE TABLE category  (
category_id  tinyint(3)  NOT NULL ,
name  varchar(25) NOT NULL, `last_update` timestamp,
PRIMARY KEY ( category_id ));

CREATE TABLE film_category  (
film_id  smallint(5)  NOT NULL,
category_id  tinyint(3)  NOT NULL, `last_update` timestamp);

輸入資料為：

INSERT INTO film VALUES(1,'ACADEMY DINOSAUR','A Epic Drama of a Feminist And a Mad Scientist who must Battle a Teacher in The Canadian Rockies');
INSERT INTO film VALUES(2,'ACE GOLDFINGER','A Astounding Epistle of a Database Administrator And a Explorer who must Find a Car in Ancient China');
INSERT INTO film VALUES(3,'ADAPTATION HOLES','A Astounding Reflection of a Lumberjack And a Car who must Sink a Lumberjack in A Baloon Factory');
INSERT INTO film VALUES(4,'AFFAIR PREJUDICE','A Fanciful Documentary of a Frisbee And a Lumberjack who must Chase a Monkey in A Shark Tank');
INSERT INTO film VALUES(5,'AFRICAN EGG','A Fast-Paced Documentary of a Pastry Chef And a Dentist who must Pursue a Forensic Psychologist in The Gulf of Mexico');
INSERT INTO film VALUES(6,'AGENT TRUMAN','A Intrepid Panorama of a robot And a Boy who must Escape a Sumo Wrestler in Ancient China');
INSERT INTO film VALUES(7,'AIRPLANE SIERRA','A Touching Saga of a Hunter And a Butler who must Discover a Butler in A Jet Boat');
INSERT INTO film VALUES(8,'AIRPORT POLLOCK','A Epic Tale of a Moose And a Girl who must Confront a Monkey in Ancient India');
INSERT INTO film VALUES(9,'ALABAMA DEVIL','A Thoughtful Panorama of a Database Administrator And a Mad Scientist who must Outgun a Mad Scientist in A Jet Boat');
INSERT INTO film VALUES(10,'ALADDIN CALENDAR','A Action-Packed Tale of a Man And a Lumberjack who must Reach a Feminist in Ancient China');

INSERT INTO category VALUES(1,'Action','2006-02-14 20:46:27');
INSERT INTO category VALUES(2,'Animation','2006-02-14 20:46:27');
INSERT INTO category VALUES(3,'Children','2006-02-14 20:46:27');
INSERT INTO category VALUES(4,'Classics','2006-02-14 20:46:27');
INSERT INTO category VALUES(5,'Comedy','2006-02-14 20:46:27');
INSERT INTO category VALUES(6,'Documentary','2006-02-14 20:46:27');
INSERT INTO category VALUES(7,'Drama','2006-02-14 20:46:27');
INSERT INTO category VALUES(8,'Family','2006-02-14 20:46:27');
INSERT INTO category VALUES(9,'Foreign','2006-02-14 20:46:27');
INSERT INTO category VALUES(10,'Games','2006-02-14 20:46:27');
INSERT INTO category VALUES(11,'Horror','2006-02-14 20:46:27');
INSERT INTO category VALUES(12,'Music','2006-02-14 20:46:27');
INSERT INTO category VALUES(13,'New','2006-02-14 20:46:27');
INSERT INTO category VALUES(14,'Sci-Fi','2006-02-14 20:46:27');
INSERT INTO category VALUES(15,'Sports','2006-02-14 20:46:27');
INSERT INTO category VALUES(16,'Travel','2006-02-14 20:46:27');

INSERT INTO film_category VALUES(1,6,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(2,11,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(3,6,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(4,11,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(5,6,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(6,6,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(7,5,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(8,6,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(9,11,'2006-02-14 21:07:09');
INSERT INTO film_category VALUES(10,15,'2006-02-14 21:07:09');

輸出：

解法
根據題目的要求可以先在film_category表中查詢電影總數量大于五部的category_id和電影數目COUNT(film_id)，然后將查詢的結果和三張表連接起來，添加題中相應的條件即可，

SELECT c.name, COUNT(fc.film_id)
FROM film AS f, film_category AS fc, category AS c,
(SELECT category_id, COUNT(film_id) AS f_count
FROM film_category
GROUP BY category_id
HAVING COUNT(film_id) >= 5) AS cc
WHERE LOCATE('robot', f.description)
AND f.film_id=fc.film_id
AND fc.category_id=c.category_id
AND cc.category_id=c.category_id