SQL29 使用join查詢方式找出沒有分類的電影id以及名稱
阿新 • • 發佈:2021-10-28
描述
film表欄位 | 說明 |
film_id | 電影id |
title | 電影名稱 |
description | 電影描述資訊 |
欄位 | 說明 |
category_id | 電影分類id |
name | 電影分類名稱 |
last_update | 電影分類最後更新時間 |
欄位 | 說明 |
film_id | 電影id |
category_id | 電影分類id |
last_update | 電影id和分類id對應關係的最後更新時間 |
輸入:
drop table if exists film ; drop table if exists category ; drop table if exists film_category ; 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); 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 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 film_category VALUES(1,6,'2006-02-14 21:07:09'); INSERT INTO film_category VALUES(2,11,'2006-02-14 21:07:09');
使用join查詢方式找出沒有分類的電影id以及名稱
3|ADAPTATION HOLES
SELECT film.film_id,film.title FROM film
LEFT JOIN film_category ON
film.film_id = film_category.film_id
WHERE film_category.category_id IS NULL