MySQL的正向工程 - SQL給錯誤121

Question

我目前正試圖用正向工程嚮導MySQL工作臺的創建我的數據庫，但我得到這個錯誤：

Executing SQL script in server 
ERROR: Error 1005: Can't create table 'microweb.users' (errno: 121) 


CREATE TABLE IF NOT EXISTS `microweb`.`users` (
    `user_id` INT UNSIGNED NOT NULL AUTO_INCREMENT , 
    `role_id` INT UNSIGNED NOT NULL , 
    `username` VARCHAR(45) NOT NULL , 
    `password` VARCHAR(45) NOT NULL , 
    `email` VARCHAR(45) NOT NULL , 
    `salt` VARCHAR(45) NOT NULL , 
    `first_name` VARCHAR(45) NOT NULL , 
    `middle_name` VARCHAR(45) NULL , 
    `last_name` VARCHAR(45) NOT NULL , 
    `address_id` INT UNSIGNED NULL , 
    `registration_id` INT UNSIGNED NOT NULL , 
    `active` TINYINT(1) NOT NULL , 
    `banned` TINYINT(1) NOT NULL , 
    PRIMARY KEY (`user_id`) , 
    UNIQUE INDEX `user_id_UNIQUE` (`user_id` ASC) , 
    UNIQUE INDEX `username_UNIQUE` (`username` ASC) , 
    UNIQUE INDEX `email_UNIQUE` (`email` ASC) , 
    UNIQUE INDEX `registration_id_UNIQUE` (`registration_id` ASC) , 
    CONSTRAINT `fk_user_role` 
    FOREIGN KEY (`role_id`) 
    REFERENCES `microweb`.`roles` (`role_id`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    CONSTRAINT `fk_user_registration` 
    FOREIGN KEY (`registration_id`) 
    REFERENCES `microweb`.`registrations` (`registration_id`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB 

SQL script execution finished: statements: 10 succeeded, 1 failed 

完整的腳本中含有大量的外鍵和21個表。問題是執行後，當Workbench說10次成功時，phpMyAdmin中只有2個。

如果有人需要完整的模型，請告訴我。

Answer 1

錯誤121表示存在重複的鍵名稱。您必須確保您自己所有的FK名稱在架構中都是唯一的。

Answer 2

我建議先嚐試一下，不要先約束，然後使用ALTER TABLE添加約束條件。

CREATE TABLE IF NOT EXISTS `microweb`.`users` (
    `user_id` INT UNSIGNED NOT NULL AUTO_INCREMENT , 
    `role_id` INT UNSIGNED NOT NULL , 
    `username` VARCHAR(45) NOT NULL , 
    `password` VARCHAR(45) NOT NULL , 
    `email` VARCHAR(45) NOT NULL , 
    `salt` VARCHAR(45) NOT NULL , 
    `first_name` VARCHAR(45) NOT NULL , 
    `middle_name` VARCHAR(45) NULL , 
    `last_name` VARCHAR(45) NOT NULL , 
    `address_id` INT UNSIGNED NULL , 
    `registration_id` INT UNSIGNED NOT NULL , 
    `active` TINYINT(1) NOT NULL , 
    `banned` TINYINT(1) NOT NULL , 
    PRIMARY KEY (`user_id`) , 
    UNIQUE INDEX `user_id_UNIQUE` (`user_id` ASC) , 
    UNIQUE INDEX `username_UNIQUE` (`username` ASC) , 
    UNIQUE INDEX `email_UNIQUE` (`email` ASC) , 
    UNIQUE INDEX `registration_id_UNIQUE` (`registration_id` ASC) 
) 
ENGINE = InnoDB; 

ALTER TABLE `microweb`.`users` 
ADD CONSTRAINT `fk_user_role` 
    FOREIGN KEY (`role_id`) 
    REFERENCES `microweb`.`roles` (`role_id`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE; 

ALTER TABLE `microweb`.`users` 
ADD CONSTRAINT `fk_user_registration` 
    FOREIGN KEY (`registration_id`) 
    REFERENCES `microweb`.`registrations` (`registration_id`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE;