mysql使用技巧之行类视图子查询

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));
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CREATE TABLE category  (


category_id  tinyint(3)  NOT NULL ,


name  varchar(25) NOT NULL, `last_update` timestamp,


PRIMARY KEY ( category_id ));
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CREATE TABLE film_category  (


film_id  smallint(5)  NOT NULL,


category_id  tinyint(3)  NOT NULL, `last_update` timestamp);
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SELECT c.name, COUNT(f.film_id) AS amount


FROM film AS f, film_category AS fc, category AS c,


(SELECT category_id FROM film_category GROUP BY category_id HAVING COUNT(category_id) >= 5) AS cc


WHERE f.description LIKE '%robot%'


AND f.film_id = fc.film_id


AND fc.category_id = c.category_id


AND c.category_id = cc.category_id
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