一、商品数据库表设计

1.1 SPU和SKU

在电商中对于商品，有两个重要的概念：SPU和SKU

1. SPU介绍      【即为商品的一个概述，一种商品的统称】

• SPU = Standard Product Unit （标准产品单位）
  • SPU是商品信息聚合的最小单位，是一组可服用、易检索的标准化信息的集合，该集合描述了一个产品的特性。
  • 通俗的讲，属性值、特性相同的商品就可以归类到一类SPU。
  • 例如:
    • iPhone X 就是一个SPU，与商家、颜色、款式、规格、套餐等都无关。

2. SKU介绍    【即为商品的一个详细信息】

• SKU = Stock Keeping Unit （库存量单位）
  • SKU即库存进出计量的单位，可以是以件、盒等为单位，是物理上不可分割的最小存货单元。
  • 通俗的讲，SKU是指一款商品，每款都有一个SKU，便于电商品牌识别商品。
  • 例如：
    • iPhone X 全网通 黑色 256G 就是一个SKU，表示了具体的规格、颜色等信息。

思考

SPU和SKU是怎样的对应关系？

• 一对一？
• 一对多？

1.2 首页广告数据库表分析

1. 首页广告数据库表分析

一对多，FK简称外键

2. 定义首页广告模型类

apps.contents.models.py

from django.db import models
from meiduo_mall.utils.models import BaseModel


# Create your models here.
class ContentCategory(BaseModel):
    """广告内容类别"""
    name = models.CharField(max_length=50, verbose_name='名称')
    key = models.CharField(max_length=50, verbose_name='类别键名')

    class Meta:
        db_table = 'tb_content_category'
        verbose_name = '广告内容类别'
        verbose_name_plural = verbose_name

    def __str__(self):
        return 


class Content(BaseModel):
    """广告内容"""
    category = models.ForeignKey(ContentCategory, on_delete=models.PROTECT, verbose_name='类别')
    title = models.CharField(max_length=100, verbose_name='标题')
    url = models.CharField(max_length=300, verbose_name='内容链接')
    image = models.ImageField(null=True, blank=True, verbose_name='图片')
    text = models.TextField(null=True, blank=True, verbose_name='内容')
    sequence = models.IntegerField(verbose_name='排序')
    status = models.BooleanField(default=True, verbose_name='是否展示')

    class Meta:
        db_table = 'tb_content'
        verbose_name = '广告内容'
        verbose_name_plural = verbose_name

    def __str__(self):
        return  + ': ' + self.title

迁移数据库：

1.3 商品信息数据库表分析

1. 商品信息数据库表分析

2. 定义商品信息模型类

新建子应用goods

在数据库迁移之前必须要注册子应用。

goods.models.py

from django.db import models
from meiduo_mall.utils.models import BaseModel


# Create your models here.
class GoodsCategory(BaseModel):
    """商品类别"""
    name = models.CharField(max_length=10, verbose_name='名称')
    parent = models.ForeignKey('self', related_name='subs', null=True, blank=True, on_delete=models.CASCADE, verbose_name='父类别')

    class Meta:
        db_table = 'tb_goods_category'
        verbose_name = '商品类别'
        verbose_name_plural = verbose_name

    def __str__(self):
        return 


class GoodsChannelGroup(BaseModel):
    """商品频道组"""
    name = models.CharField(max_length=20, verbose_name='频道组名')

    class Meta:
        db_table = 'tb_channel_group'
        verbose_name = '商品频道组'
        verbose_name_plural = verbose_name

    def __str__(self):
        return 


class GoodsChannel(BaseModel):
    """商品频道"""
    group = models.ForeignKey(GoodsChannelGroup, verbose_name='频道组名')
    category = models.ForeignKey(GoodsCategory, on_delete=models.CASCADE, verbose_name='顶级商品类别')
    url = models.CharField(max_length=50, verbose_name='频道页面链接')
    sequence = models.IntegerField(verbose_name='组内顺序')

    class Meta:
        db_table = 'tb_goods_channel'
        verbose_name = '商品频道'
        verbose_name_plural = verbose_name

    def __str__(self):
        return 


class Brand(BaseModel):
    """品牌"""
    name = models.CharField(max_length=20, verbose_name='名称')
    logo = models.ImageField(verbose_name='Logo图片')
    first_letter = models.CharField(max_length=1, verbose_name='品牌首字母')

    class Meta:
        db_table = 'tb_brand'
        verbose_name = '品牌'
        verbose_name_plural = verbose_name

    def __str__(self):
        return 


class SPU(BaseModel):
    """商品SPU"""
    name = models.CharField(max_length=50, verbose_name='名称')
    brand = models.ForeignKey(Brand, on_delete=models.PROTECT, verbose_name='品牌')
    category1 = models.ForeignKey(GoodsCategory, on_delete=models.PROTECT, related_name='cat1_spu', verbose_name='一级类别')
    category2 = models.ForeignKey(GoodsCategory, on_delete=models.PROTECT, related_name='cat2_spu', verbose_name='二级类别')
    category3 = models.ForeignKey(GoodsCategory, on_delete=models.PROTECT, related_name='cat3_spu', verbose_name='三级类别')
    sales = models.IntegerField(default=0, verbose_name='销量')
    comments = models.IntegerField(default=0, verbose_name='评价数')
    desc_detail = models.TextField(default='', verbose_name='详细介绍')
    desc_pack = models.TextField(default='', verbose_name='包装信息')
    desc_service = models.TextField(default='', verbose_name='售后服务')

    class Meta:
        db_table = 'tb_spu'
        verbose_name = '商品SPU'
        verbose_name_plural = verbose_name

    def __str__(self):
        return 


class SKU(BaseModel):
    """商品SKU"""
    name = models.CharField(max_length=50, verbose_name='名称')
    caption = models.CharField(max_length=100, verbose_name='副标题')
    spu = models.ForeignKey(SPU, on_delete=models.CASCADE, verbose_name='商品')
    category = models.ForeignKey(GoodsCategory, on_delete=models.PROTECT, verbose_name='从属类别')
    price = models.DecimalField(max_digits=10, decimal_places=2, verbose_name='单价')
    cost_price = models.DecimalField(max_digits=10, decimal_places=2, verbose_name='进价')
    market_price = models.DecimalField(max_digits=10, decimal_places=2, verbose_name='市场价')
    stock = models.IntegerField(default=0, verbose_name='库存')
    sales = models.IntegerField(default=0, verbose_name='销量')
    comments = models.IntegerField(default=0, verbose_name='评价数')
    is_launched = models.BooleanField(default=True, verbose_name='是否上架销售')
    default_image_url = models.CharField(max_length=200, default='', null=True, blank=True, verbose_name='默认图片')

    class Meta:
        db_table = 'tb_sku'
        verbose_name = '商品SKU'
        verbose_name_plural = verbose_name

    def __str__(self):
        return '%s: %s' % (self.id, )


class SKUImage(BaseModel):
    """SKU图片"""
    sku = models.ForeignKey(SKU, on_delete=models.CASCADE, verbose_name='sku')
    image = models.ImageField(verbose_name='图片')

    class Meta:
        db_table = 'tb_sku_image'
        verbose_name = 'SKU图片'
        verbose_name_plural = verbose_name

    def __str__(self):
        return '%s %s' % (, self.id)


class SPUSpecification(BaseModel):
    """商品SPU规格"""
    spu = models.ForeignKey(SPU, on_delete=models.CASCADE, related_name='specs', verbose_name='商品SPU')
    name = models.CharField(max_length=20, verbose_name='规格名称')

    class Meta:
        db_table = 'tb_spu_specification'
        verbose_name = '商品SPU规格'
        verbose_name_plural = verbose_name

    def __str__(self):
        return '%s: %s' % (, )


class SpecificationOption(BaseModel):
    """规格选项"""
    spec = models.ForeignKey(SPUSpecification, related_name='options', on_delete=models.CASCADE, verbose_name='规格')
    value = models.CharField(max_length=20, verbose_name='选项值')

    class Meta:
        db_table = 'tb_specification_option'
        verbose_name = '规格选项'
        verbose_name_plural = verbose_name

    def __str__(self):
        return '%s - %s' % (self.spec, self.value)


class SKUSpecification(BaseModel):
    """SKU具体规格"""
    sku = models.ForeignKey(SKU, related_name='specs', on_delete=models.CASCADE, verbose_name='sku')
    spec = models.ForeignKey(SPUSpecification, on_delete=models.PROTECT, verbose_name='规格名称')
    option = models.ForeignKey(SpecificationOption, on_delete=models.PROTECT, verbose_name='规格值')

    class Meta:
        db_table = 'tb_sku_specification'
        verbose_name = 'SKU规格'
        verbose_name_plural = verbose_name

    def __str__(self):
        return '%s: %s - %s' % (self.sku, , self.option.value)

数据库迁移：