本篇文章和大家了解一下mysql行类视图子查询相关介绍。有一定的参考价值,有需要的朋友可以参考一下,希望对大家有所帮助。
查找描述信息中包括robot的电影对应的分类名称以及电影数目,而且还需要该分类对应电影数量>=5部
film表为电影表,category表为电影分类表,film_category表为电影表与电影分类表的中间表(多对多的中间表)
film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));
category表

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

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
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