film表
| 字段 |
说明 |
| film_id |
电影id |
| title |
电影名称 |
| description |
电影描述信息 |
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));
category表
| 字段 |
说明 |
| category_id |
电影分类id |
| name |
电影分类名称 |
| last_update |
电影分类最后更新时间 |
CREATE TABLE category (
category_id tinyint(3) NOT NULL ,
name varchar(25) NOT NULL, `last_update` timestamp,
PRIMARY KEY ( category_id ));
film_category表
| 字段 |
说明 |
| film_id |
电影id |
| category_id |
电影分类id |
| last_update |
电影id和分类id对应关系的最后更新时间 |
CREATE TABLE film_category (
film_id smallint(5) NOT NULL,
category_id tinyint(3) NOT NULL, `last_update` timestamp);
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
