如何通过一个查询删除两个链接表(多对多关系)中的数据?

How to delete data in two linked tables (many-to-many relationship) with one query?

有tables films,actors和table绑定他们films_actors.

创建代码:

CREATE TABLE `actors` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`first_name` VARCHAR(50) NOT NULL,
`surname` VARCHAR(50) NOT NULL,
PRIMARY KEY (`id`)
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
AUTO_INCREMENT=9
;

CREATE TABLE `films` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`title` VARCHAR(255) NOT NULL,
`release` SMALLINT(4) NOT NULL,
`format` VARCHAR(10) NOT NULL,
PRIMARY KEY (`id`)
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
AUTO_INCREMENT=6
;
CREATE TABLE `films_actors` (
`id_film` INT(11) NOT NULL,
`id_actor` INT(11) NOT NULL,
INDEX `FK_films_actors_actors` (`id_actor`),
INDEX `FK_films_actors_films` (`id_film`),
CONSTRAINT `FK_films_actors_actors` FOREIGN KEY (`id_actor`) REFERENCES `actors` (`id`) ON UPDATE CASCADE ON DELETE CASCADE,
CONSTRAINT `FK_films_actors_films` FOREIGN KEY (`id_film`) REFERENCES `films` (`id`) ON UPDATE CASCADE ON DELETE CASCADE
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
;

如果我从tableactorsfilms中删除数据,那么films_actorstable中的数据会自动删除,问题是一个查询是否可以一次从所有三个 table 中删除数据?

这是我尝试编写但没有成功的查询。

delete
from films, actors
where actors.id in (
select films_actors.id_actor from films_actors 
where films_actors.id_film = 5
) and films.id = films_actors.id_film

您可以使用删除联接并在联接中使用子查询来管理 IN 子句

    delete films.*, actors.*
from films
INNER JOIN (
    select films_actors.id_actor, id_film
    from films_actors 
    where films_actors.id_film = 5
)  t  ON films.id = t.id_film
INNER JOIN  actors ON actors.id = t.id_actor 

你应该可以做到:

delete f, a, fa
from films f join
     films_actors fa
     on fa.id_film = f.id join
     actors a
     on fa.id_actor = a.id
where f.id = 5;

这看起来很危险,因为演员可能在其他电影中。我假设您真的只想从 ffa.

中删除