相关疑难解决方法(0)

我有几个表,我想从PDF表中引用一列到多个其他表.

例如,如果PDF表格select输出如下所示:

ITEM_TYPE  ITEM_ID  QUANTITY

1          23       3
2          12       1

它告诉我:

PDF上面有3个车轮产品和1个车模板标题;

我编写了SQL代码,但无法正常工作:

CREATE TABLE `pdf_created` (
    `id` INT(10) UNSIGNED NOT NULL UNIQUE AUTO_INCREMENT,
    `pdf_id` INT(10) NOT NULL,
    `item_type` INT(3) UNSIGNED NOT NULL,
    `item_id` INT(10) UNSIGNED NOT NULL,
    `quantity` INT(3) NOT NULL,
    PRIMARY KEY (`id`),
    KEY `FK_pdf_id` (`pdf_id`),
    CONSTRAINT `FK_pdf_id` FOREIGN KEY (`pdf_id`) REFERENCES `pdf` (`id`),
    KEY `FK_item_type` (`item_type`),
    CONSTRAINT `FK_item_type` FOREIGN KEY (`item_type`) REFERENCES `item` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
    KEY `FK_item_id` (`item_id`),
    CONSTRAINT …