MySQL命名规范最佳实践之数据库、表、字段等命名规则与行业标准

-- 合法命名示例
CREATE DATABASE ecommerce_db;
CREATE TABLE user_accounts (id INT, username VARCHAR(50));

-- 非法命名示例
CREATE DATABASE 123db;  -- 以数字开头
CREATE TABLE select (id INT);  -- 使用保留字

-- 开发环境
CREATE DATABASE eshop_dev;

-- 测试环境
CREATE DATABASE eshop_test;

-- 生产环境
CREATE DATABASE eshop_prod;

-- 用户服务
CREATE DATABASE svc_user;

-- 订单服务
CREATE DATABASE svc_order;

-- 支付服务
CREATE DATABASE svc_payment;

-- 基础表
CREATE TABLE products (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  name VARCHAR(100) NOT NULL,
  price DECIMAL(10,2) NOT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- 关联表
CREATE TABLE product_categories (
  product_id INT UNSIGNED NOT NULL,
  category_id INT UNSIGNED NOT NULL,
  PRIMARY KEY (product_id, category_id),
  FOREIGN KEY (product_id) REFERENCES products(id),
  FOREIGN KEY (category_id) REFERENCES categories(id)
);

-- 日志表
CREATE TABLE price_change_history (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  product_id INT UNSIGNED NOT NULL,
  old_price DECIMAL(10,2) NOT NULL,
  new_price DECIMAL(10,2) NOT NULL,
  changed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  changed_by INT UNSIGNED NOT NULL,
  PRIMARY KEY (id),
  FOREIGN KEY (product_id) REFERENCES products(id)
);

CREATE TABLE employees (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  first_name VARCHAR(50) NOT NULL,
  last_name VARCHAR(50) NOT NULL,
  email VARCHAR(100) UNIQUE NOT NULL,
  hire_date DATE NOT NULL,
  is_active TINYINT(1) DEFAULT 1,
  department_id INT UNSIGNED,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  FOREIGN KEY (department_id) REFERENCES departments(id)
);

CREATE TABLE blog_posts (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  title VARCHAR(255) NOT NULL,
  slug VARCHAR(255) UNIQUE NOT NULL,
  content TEXT NOT NULL,
  author_id INT UNSIGNED NOT NULL,
  category_id INT UNSIGNED,
  is_published TINYINT(1) DEFAULT 0,
  view_count INT UNSIGNED DEFAULT 0,
  meta_description VARCHAR(160),
  published_at DATETIME,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  FOREIGN KEY (author_id) REFERENCES users(id),
  FOREIGN KEY (category_id) REFERENCES blog_categories(id),
  INDEX idx_slug (slug),
  INDEX idx_published (is_published, published_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- 用户表结构
CREATE TABLE users (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  username VARCHAR(50) NOT NULL,
  email VARCHAR(100) NOT NULL,
  phone VARCHAR(20),
  country_code CHAR(2),
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  UNIQUE INDEX uniq_users_username (username),
  UNIQUE INDEX uniq_users_email (email),
  INDEX idx_users_phone (phone),
  INDEX idx_users_country_created (country_code, created_at)
);

-- 订单表结构
CREATE TABLE orders (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  user_id INT UNSIGNED NOT NULL,
  order_number VARCHAR(20) NOT NULL,
  status ENUM('pending','processing','shipped','delivered','cancelled') DEFAULT 'pending',
  total_amount DECIMAL(12,2) NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  UNIQUE INDEX uniq_orders_number (order_number),
  INDEX idx_orders_user_status (user_id, status),
  INDEX idx_orders_created (created_at),
  FOREIGN KEY (user_id) REFERENCES users(id)
);

-- 产品分类表
CREATE TABLE product_categories (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  name VARCHAR(50) NOT NULL,
  slug VARCHAR(50) NOT NULL,
  parent_id INT UNSIGNED,
  display_order INT NOT NULL DEFAULT 0,
  is_active TINYINT(1) NOT NULL DEFAULT 1,
  CONSTRAINT PK_product_categories PRIMARY KEY (id),
  CONSTRAINT UQ_product_categories_name UNIQUE (name),
  CONSTRAINT UQ_product_categories_slug UNIQUE (slug),
  CONSTRAINT FK_product_categories_parent FOREIGN KEY (parent_id) 
    REFERENCES product_categories(id),
  CONSTRAINT CK_product_categories_display_order CHECK (display_order >= 0)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- 产品表
CREATE TABLE products (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  category_id INT UNSIGNED NOT NULL,
  sku VARCHAR(20) NOT NULL,
  name VARCHAR(100) NOT NULL,
  description TEXT,
  price DECIMAL(10,2) NOT NULL,
  stock_quantity INT NOT NULL DEFAULT 0,
  weight DECIMAL(8,2),
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  CONSTRAINT PK_products PRIMARY KEY (id),
  CONSTRAINT UQ_products_sku UNIQUE (sku),
  CONSTRAINT FK_products_category FOREIGN KEY (category_id) 
    REFERENCES product_categories(id),
  CONSTRAINT CK_products_price CHECK (price > 0),
  CONSTRAINT CK_products_stock CHECK (stock_quantity >= 0),
  CONSTRAINT CK_products_weight CHECK (weight > 0)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- 用户相关函数
DELIMITER //

CREATE FUNCTION func_get_user_full_name(user_id INT) 
RETURNS VARCHAR(201)
READS SQL DATA
BEGIN
  DECLARE full_name VARCHAR(201);
  
  SELECT CONCAT(first_name, ' ', last_name) INTO full_name
  FROM users
  WHERE id = user_id;
  
  RETURN full_name;
END//

-- 订单相关存储过程
CREATE PROCEDURE sp_create_order(
  IN p_user_id INT,
  IN p_product_ids TEXT,
  IN p_quantities TEXT,
  OUT p_order_id INT
)
BEGIN
  DECLARE EXIT HANDLER FOR SQLEXCEPTION
  BEGIN
    ROLLBACK;
    RESIGNAL;
  END;
  
  START TRANSACTION;
  
  -- 创建订单主记录
  INSERT INTO orders (user_id, order_date, status)
  VALUES (p_user_id, NOW(), 'pending');
  
  SET p_order_id = LAST_INSERT_ID();
  
  -- 添加订单项
  -- 这里需要实现解析p_product_ids和p_quantities的逻辑
  -- 可能是使用循环或临时表处理
  
  COMMIT;
END//

DELIMITER ;

-- 销售报表视图
CREATE VIEW vw_sales_report AS
SELECT 
  DATE(o.order_date) AS sale_date,
  c.name AS category_name,
  p.name AS product_name,
  SUM(oi.quantity) AS total_quantity,
  SUM(oi.quantity * oi.unit_price) AS total_revenue,
  COUNT(DISTINCT o.user_id) AS unique_customers,
  COUNT(DISTINCT o.id) AS order_count
FROM orders o
JOIN order_items oi ON o.id = oi.order_id
JOIN products p ON oi.product_id = p.id
JOIN product_categories c ON p.category_id = c.id
WHERE o.status = 'delivered'
GROUP BY DATE(o.order_date), c.name, p.name
ORDER BY sale_date DESC, total_revenue DESC;

-- 用户活跃度视图
CREATE VIEW vw_user_activity AS
SELECT 
  u.id AS user_id,
  u.username,
  u.email,
  COUNT(o.id) AS order_count,
  MAX(o.order_date) AS last_order_date,
  DATEDIFF(CURRENT_DATE, MAX(o.order_date)) AS days_since_last_order,
  SUM(o.total_amount) AS lifetime_value,
  CASE
    WHEN COUNT(o.id) = 0 THEN 'new'
    WHEN DATEDIFF(CURRENT_DATE, MAX(o.order_date)) <= 30 THEN 'active'
    WHEN DATEDIFF(CURRENT_DATE, MAX(o.order_date)) <= 90 THEN 'lapsing'
    ELSE 'inactive'
  END AS activity_status
FROM users u
LEFT JOIN orders o ON u.id = o.user_id AND o.status = 'delivered'
GROUP BY u.id, u.username, u.email;

DELIMITER //

-- 库存更新触发器
CREATE TRIGGER trg_order_items_after_insert_update_inventory
AFTER INSERT ON order_items
FOR EACH ROW
BEGIN
  -- 减少产品库存
  UPDATE products 
  SET stock_quantity = stock_quantity - NEW.quantity
  WHERE id = NEW.product_id;
  
  -- 记录库存变更
  INSERT INTO inventory_transactions
  (product_id, quantity_change, transaction_type, reference_id, created_at)
  VALUES (NEW.product_id, -NEW.quantity, 'order', NEW.order_id, NOW());
END//

-- 订单状态变更触发器
CREATE TRIGGER trg_orders_after_update_status_change
AFTER UPDATE ON orders
FOR EACH ROW
BEGIN
  IF OLD.status != NEW.status THEN
    -- 记录状态变更历史
    INSERT INTO order_status_history
    (order_id, old_status, new_status, changed_at, changed_by)
    VALUES (NEW.id, OLD.status, NEW.status, NOW(), @current_user_id);
    
    -- 如果订单发货，发送通知
    IF NEW.status = 'shipped' THEN
      INSERT INTO notifications
      (user_id, notification_type, title, message, created_at)
      VALUES (
        NEW.user_id, 
        'order_shipped', 
        '您的订单已发货', 
        CONCAT('订单 #', NEW.order_number, ' 已发货'), 
        NOW()
      );
    END IF;
  END IF;
END//

DELIMITER ;

-- CRM模块数据库
CREATE DATABASE crm_prod;

-- 用户表按地区分区
CREATE TABLE crm_prod.customers (
  id INT NOT NULL AUTO_INCREMENT,
  name VARCHAR(100) NOT NULL,
  email VARCHAR(100) NOT NULL,
  region ENUM('north','south','east','west') NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (id, region)
)
PARTITION BY LIST COLUMNS(region) (
  PARTITION p_north VALUES IN ('north'),
  PARTITION p_south VALUES IN ('south'),
  PARTITION p_east VALUES IN ('east'),
  PARTITION p_west VALUES IN ('west')
);

-- 订单表按年份范围分区
CREATE TABLE crm_prod.orders (
  id INT NOT NULL AUTO_INCREMENT,
  customer_id INT NOT NULL,
  order_date DATE NOT NULL,
  amount DECIMAL(10,2) NOT NULL,
  PRIMARY KEY (id, order_date)
)
PARTITION BY RANGE (YEAR(order_date)) (
  PARTITION p_2020 VALUES LESS THAN (2021),
  PARTITION p_2021 VALUES LESS THAN (2022),
  PARTITION p_2022 VALUES LESS THAN (2023),
  PARTITION p_2023 VALUES LESS THAN (2024),
  PARTITION p_future VALUES LESS THAN MAXVALUE
);

-- 用户服务数据库
CREATE DATABASE svc_user_prod;

-- 用户核心表
CREATE TABLE svc_user_prod.users (
  user_id VARCHAR(36) NOT NULL,  -- UUID
  username VARCHAR(50) NOT NULL,
  email VARCHAR(100) NOT NULL,
  password_hash VARCHAR(255) NOT NULL,
  is_active BOOLEAN DEFAULT TRUE,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (user_id),
  UNIQUE INDEX uniq_users_username (username),
  UNIQUE INDEX uniq_users_email (email)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- 订单服务数据库
CREATE DATABASE svc_order_prod;

-- 订单表
CREATE TABLE svc_order_prod.orders (
  order_id VARCHAR(36) NOT NULL,  -- UUID
  user_id VARCHAR(36) NOT NULL,   -- 引用用户服务的UUID
  order_number VARCHAR(20) NOT NULL,
  status ENUM('created','paid','shipped','completed','cancelled') NOT NULL,
  total_amount DECIMAL(12,2) NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (order_id),
  UNIQUE INDEX uniq_orders_number (order_number),
  INDEX idx_orders_user (user_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;