Once ...
a table `abbott_wp6`.`wp_wpinventory_item` exists with column
inventory_id int as a primary key,
);
... and a table `abbott_wp6`.`wp_wpinventory_category exists with column
category_id`int as a primary key,
then this works:
CREATE TABLE `abbott_wp6`.`kbo_inventorycategory` (
`inventorycategory_id` INT NOT NULL AUTO_INCREMENT,
`inventory_id` INT NOT NULL,
`category_id` INT NOT NULL,
`category_type` VARCHAR(10) NOT NULL DEFAULT 'subject'
COMMENT 'age, subject, teacher, bargain, new, under2',
PRIMARY KEY (`inventorycategory_id`),
INDEX `fk_inventorycatalog_inventory_idx` (`inventory_id` ASC) VISIBLE,
INDEX `fk_inventorycaegory_category_idx` (`category_id` ASC) VISIBLE,
CONSTRAINT `fk_inventorycategory_inventory` FOREIGN KEY (`inventory_id`)
REFERENCES `abbott_wp6`.`wp_wpinventory_item` (`inventory_id`)
ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `fk_inventorycategory_category` FOREIGN KEY (`category_id`)
REFERENCES `abbott_wp6`.`wp_wpinventory_category` (`category_id`)
ON DELETE NO ACTION ON UPDATE NO ACTION
);