MySQL 教程：概述

CREATE DATABASE IF NOT EXISTS shop;
USE shop;

CREATE TABLE users (
  id BIGINT PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(100) NOT NULL,
  email VARCHAR(255) NOT NULL UNIQUE,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB;

CREATE TABLE products (
  id BIGINT PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(200) NOT NULL,
  price DECIMAL(10,2) NOT NULL,
  stock INT NOT NULL DEFAULT 0,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  KEY idx_price (price)
) ENGINE=InnoDB;

CREATE TABLE orders (
  id BIGINT PRIMARY KEY AUTO_INCREMENT,
  user_id BIGINT NOT NULL,
  total DECIMAL(10,2) NOT NULL,
  status ENUM('CREATED','PAID','CANCELLED') NOT NULL,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (user_id) REFERENCES users(id)
) ENGINE=InnoDB;

CREATE TABLE order_items (
  id BIGINT PRIMARY KEY AUTO_INCREMENT,
  order_id BIGINT NOT NULL,
  product_id BIGINT NOT NULL,
  quantity INT NOT NULL,
  price DECIMAL(10,2) NOT NULL,
  FOREIGN KEY (order_id) REFERENCES orders(id),
  FOREIGN KEY (product_id) REFERENCES products(id),
  KEY idx_order (order_id),
  KEY idx_product (product_id)
) ENGINE=InnoDB;