Imam jednu join tabelu koja ima samo dvije kolone, odnosno dva foreing key-ja. Mislio sam da stavim kompozitni ključ tako da obe kolone čine PRIMARY KEY.
E sad, kako da napravim foreign key relacije? Jer sad kako sam uradio dobijam grešku ERROR 1022 (23000): Can't write; duplicate key in table 'article_category'
E sad, kako da napravim foreign key relacije? Jer sad kako sam uradio dobijam grešku ERROR 1022 (23000): Can't write; duplicate key in table 'article_category'
Code:
CREATE TABLE IF NOT EXISTS `nii`.`article_category` (
`article_id` INT UNSIGNED NOT NULL,
`category_id` MEDIUMINT UNSIGNED NOT NULL,
PRIMARY KEY (`category_id`, `article_id`),
CONSTRAINT `fk_article_id`
FOREIGN KEY (`article_id`)
REFERENCES `nii`.`article` (`id`)
ON DELETE RESTRICT
ON UPDATE CASCADE,
CONSTRAINT `fk_category_id`
FOREIGN KEY (`category_id`)
REFERENCES `nii`.`category` (`id`)
ON DELETE RESTRICT
ON UPDATE CASCADE)
ENGINE = InnoDB
CREATE TABLE IF NOT EXISTS `nii`.`article_category` (
`article_id` INT UNSIGNED NOT NULL,
`category_id` MEDIUMINT UNSIGNED NOT NULL,
PRIMARY KEY (`category_id`, `article_id`),
CONSTRAINT `fk_article_id`
FOREIGN KEY (`article_id`)
REFERENCES `nii`.`article` (`id`)
ON DELETE RESTRICT
ON UPDATE CASCADE,
CONSTRAINT `fk_category_id`
FOREIGN KEY (`category_id`)
REFERENCES `nii`.`category` (`id`)
ON DELETE RESTRICT
ON UPDATE CASCADE)
ENGINE = InnoDB
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