MYSQL 商城系统设计 商品数据表的设计 商品 商品类别 商品选项卡 多表查询

介绍

在开发商品模块时，通常使用分表的方式进行查询以及关联。在通过表连接的方式进行查询。每个商品都有不同的分类，每个不同分类下面都有商品规格可以选择，每个商品分类对应商品规格都有自己的价格和库存。在实际的开发中应该给这些表进行外键的约束避免垃圾无用的数据 。

最终效果

{
    "id": 541834,
    "productName": "Kiei",
    "product": { //商品的全部信息
        "productId": 541834,
        "productName": "Kiei",
        "price": 416.83,
        "description": "Navicat Cloud could not connect and access your databases. By which it means, it could only store your connection settings, queries, model files, and virtual group; your database passwords            ",
        "createdAt": "2010-08-07T23:54:41"
    },
    "classification": { //商品的类别
        "id": 1,
        "majorCategories": {
            "id": 1,
            "majorCategories": "家电",
            "smallCategory": {
                "id": 2,
                "smallCategory": "空调"
            }
        }
    },
    "categories": [ //商品购买时选项名称
        {
            "categoryId": 228788,
            "categoryName": "运动与户外用品",
            "sortOrder": 1,//前端根据这个字段排序
            "options": [ //商品具体购买项
                {
                    "optionId": 375246,
                    "productId": 541834,
                    "categoryId": 228788,
                    "optionValue": "White Smoke",
                    "sortOrder": null //前端根据这个字段排序
                }
            ]
        },
        {
            "categoryId": 237990,
            "categoryName": "Apps & Games",
            "sortOrder": 0,  //前端根据这个字段排序
            "options": [
                {
                    "optionId": 118132,
                    "productId": 541834,
                    "categoryId": 237990,
                    "optionValue": "雾玫瑰色",
                    "sortOrder": null //前端根据这个字段排序
                }
            ]
        }
    ]
}

创建商品表

category_id关联的是 商品大类 和 商品小类 的中间表字段

/*
 Navicat Premium Dump SQL

 Source Server         : local
 Source Server Type    : MySQL
 Source Server Version : 80012 (8.0.12)
 Source Host           : localhost:3306
 Source Schema         : java-test

 Target Server Type    : MySQL
 Target Server Version : 80012 (8.0.12)
 File Encoding         : 65001

 Date: 29/01/2025 18:19:06
*/

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for products
-- ----------------------------
DROP TABLE IF EXISTS `products`;
CREATE TABLE `products`  (
  `product_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '商品ID',
  `product_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT '商品名称',
  `price` decimal(10, 2) NULL DEFAULT NULL COMMENT '商品价格',
  `description` text CHARACTER SET utf8 COLLATE utf8_bin NULL COMMENT '商品描述',
  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `category_id` int(11) NULL DEFAULT NULL COMMENT '类目ID',
  PRIMARY KEY (`product_id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1541834 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;

创建商品大类表

该表只存储大类的商品信息不存其他信息，而其他商品信息应该保存在中间表当中。这样是为了防止结构的耦合。

CREATE TABLE `java-test`.`Untitled`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `major_categories` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL COMMENT '大类',
  PRIMARY KEY (`id`) USING BTREE,
  INDEX `idx_id_major_categories`(`id`, `major_categories`) USING BTREE
) ENGINE = MyISAM AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

创建商品小类表

该表只存储商品的小类

CREATE TABLE `java-test`.`Untitled`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `small_category` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL COMMENT '小类名称',
  PRIMARY KEY (`id`) USING BTREE,
  INDEX `idx_id_small_category`(`id`, `small_category`) USING BTREE
) ENGINE = MyISAM AUTO_INCREMENT = 3 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

创建大类小类中间表

ID字段被商品表的category_id关联。

CREATE TABLE `java-test`.`Untitled`  (
  `id` int(11) NOT NULL,
  `major_categories_id` int(11) NULL DEFAULT NULL COMMENT '大类ID',
  `small_category_id` int(11) NULL DEFAULT NULL COMMENT '小类ID',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = MyISAM AUTO_INCREMENT = 1 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Fixed;

创建套餐表

CREATE TABLE `java-test`.`Untitled`  (
  `category_id` int(11) NOT NULL AUTO_INCREMENT,
  `category_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT '套餐类别',
  PRIMARY KEY (`category_id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 516019 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

套餐选项表

套餐选项包含商品的ID和套餐的ID

CREATE TABLE `java-test`.`Untitled`  (
  `option_id` int(11) NOT NULL AUTO_INCREMENT,
  `product_id` int(11) NULL DEFAULT NULL COMMENT '商品ID',
  `category_id` int(11) NULL DEFAULT NULL COMMENT '套餐ID',
  `option_value` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT '套餐名称',
  `sort_order` int(11) NULL DEFAULT NULL COMMENT '排序字段',
  PRIMARY KEY (`option_id`) USING BTREE,
  INDEX `idx_po_product_category`(`product_id` ASC, `category_id` ASC) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 3000005 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

套餐中间表

CREATE TABLE `java-test`.`Untitled`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '编号',
  `category_id` int(11) NOT NULL COMMENT '商品套餐',
  `sort_order` int(11) NOT NULL COMMENT '套餐排序',
  PRIMARY KEY (`id`, `category_id`) USING BTREE,
  INDEX `idx_category_sort_order`(`category_id` ASC, `sort_order` ASC) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 3000001 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

查询语句

要求查询出 商品信息 商品大类小类 商品套餐 套餐里的选项

 SELECT
    p.product_id,
    p.product_name,
    p.price,
    p.description,
    p.created_at,
    ma.id major_categories_id ,
    ma.major_categories,
    sm.small_category,
    sm.id small_category_id,
    c.id classification_id,
    pc.category_name,
    pc.category_id,
    po.option_value,
    po.option_id,
    po.sort_order option_index,
    so.sort_order category_index
FROM products p
    LEFT JOIN classification c ON p.category_id = c.id 
    LEFT JOIN major_categories ma ON c.major_categories_id = ma.id  
    LEFT JOIN small_category sm ON c.small_category_id = sm.id  
    LEFT JOIN product_options po ON p.product_id = po.product_id
    LEFT JOIN product_categories pc ON po.category_id = pc.category_id
    LEFT JOIN category_association so ON so.category_id = po.category_id
WHERE p.product_id = 541834;

查询性能