SET FOREIGN_KEY_CHECKS = 0;

alter TABLE `vendor_contacts` 
	change `vc_vendor_id` `vc_vendor_id` MEDIUMINT(8) UNSIGNED NOT NULL;
alter TABLE `vendors`
	change `vn_id` `vn_id` MEDIUMINT(8) UNSIGNED NOT NULL AUTO_INCREMENT;

SET FOREIGN_KEY_CHECKS = 1;

SQL Error (1025): Error on rename of './zntral/#sql-40b_3' to './zntral/vendor_contacts' (errno: 150 - Foreign key constraint is incorrectly formed)

CREATE TABLE `vendor_contacts` (
	`vc_id` MEDIUMINT(8) NOT NULL AUTO_INCREMENT,
	`vc_vendor_id` MEDIUMINT(8) NOT NULL,
	`vc_person_name` VARCHAR(50) NOT NULL,
	`vc_person_description` VARCHAR(255) NOT NULL,
	`vc_phone` VARCHAR(50) NOT NULL,
	`vc_phone_description` VARCHAR(255) NOT NULL,
	`vc_person_email` VARCHAR(50) NOT NULL,
	`created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
	`updated_at` DATETIME NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
	PRIMARY KEY (`vc_id`),
	UNIQUE INDEX `ind_vendors_have_types_vc_vendor_id_vc_person_name` (`vc_vendor_id`, `vc_person_name`),
	INDEX `ind_vendor_contacts_created_at` (`created_at`),
	CONSTRAINT `fk_vendor_contacts_vc_vendor_id` FOREIGN KEY (`vc_vendor_id`) REFERENCES `vendors` (`vn_id`) ON UPDATE NO ACTION ON DELETE NO ACTION