在powerdesign中使用sql语句逆向生成pdm

DROP DATABASE IF EXISTS test;
CREATE DATABASE test;
USE test;

DROP TABLE IF EXISTS user;
DROP TABLE IF EXISTS blog;
DROP TABLE IF EXISTS comment;
DROP TABLE IF EXISTS category;

CREATE TABLE user (
id            INT AUTO_INCREMENT PRIMARY KEY,
username      VARCHAR(200) UNIQUE,
password      VARCHAR(200) NOT NULL
);

CREATE TABLE category (
id          INT AUTO_INCREMENT PRIMARY KEY,
name        VARCHAR(200) NOT NULL
);

CREATE TABLE blog (
id          INT AUTO_INCREMENT PRIMARY KEY,
category    INT,
title       VARCHAR(200) NOT NULL,
content     TEXT         NOT NULL,
author      INT          NOT NULL,
create_time DATETIME     NOT NULL,
FOREIGN KEY (author) REFERENCES user (id),
FOREIGN KEY (category) REFERENCES category (id) ON DELETE CASCADE
);

CREATE TABLE comment (
id          INT AUTO_INCREMENT PRIMARY KEY,
content     TEXT         NOT NULL,
create_time DATETIME     NOT NULL,
author      INT,
blog        INT,
FOREIGN KEY (author) REFERENCES user (id),
FOREIGN KEY (blog) REFERENCES blog (id) ON DELETE CASCADE
);