一、数据库设计:

在电商中对于商品,有两个重要的概念:

SPU

和

SKU

• 
  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称为一个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。
• 
  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、托盘等为单位，是物理上不可分割的最小存货单元。在使用时要根据不同业态，不同管理模式来处理。在服装、鞋类商品中使用最多最普遍。
  
  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。

1.表结构:

1.1商品数据表结构:

1.2 首页广告数据表结构:

二、创建数据库模型类:

1. 创建商品子应用并注册:

创建商品应用goods,

 python ../../manage.py startapp goods

注册子应用:

# /setting/dev.py
...
INSTALLED_APPS = [
    ...
    'goods.apps.GoodsConfig',
]
...

2.定义商品数据模型类:

# /apps/goods/models.py

from django.db import models

# Create your models here.
from utils.models import BaseModel


class GoodsCategory(BaseModel):
    """
    商品类别
    """
    name = models.CharField(max_length=10, verbose_name='名称')
    parent = models.ForeignKey('self', 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 self.name


class GoodsChannel(BaseModel):
    """
    商品频道
    """
    group_id = models.IntegerField(verbose_name='组号')
    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 self.category.name


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 self.name


class Goods(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_goods', verbose_name='一级类别')
    category2 = models.ForeignKey(GoodsCategory, on_delete=models.PROTECT, related_name='cat2_goods', verbose_name='二级类别')
    category3 = models.ForeignKey(GoodsCategory, on_delete=models.PROTECT, related_name='cat3_goods', 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')

    class Meta:
        db_table = 'tb_goods'
        verbose_name = '商品'
        verbose_name_plural = verbose_name

    def __str__(self):
        return self.name


class GoodsSpecification(BaseModel):
    """
    商品规格
    """
    goods = models.ForeignKey(Goods, on_delete=models.CASCADE, verbose_name='商品')
    name = models.CharField(max_length=20, verbose_name='规格名称')

    class Meta:
        db_table = 'tb_goods_specification'
        verbose_name = '商品规格'
        verbose_name_plural = verbose_name

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


class SpecificationOption(BaseModel):
    """
    规格选项
    """
    spec = models.ForeignKey(GoodsSpecification, 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 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')
    goods = models.ForeignKey(Goods, 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, self.name)


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.sku.name, self.id)


class SKUSpecification(BaseModel):
    """
    SKU具体规格
    """
    sku = models.ForeignKey(SKU, on_delete=models.CASCADE, verbose_name='sku')
    spec = models.ForeignKey(GoodsSpecification, 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.spec.name, self.option.value)

3. 创建广告内容应用contents并注册

创建商品应用goods,

 python ../../manage.py startapp contents

注册子应用:

# /setting/dev.py
...
INSTALLED_APPS = [
    ...
    'contents.apps.ContentsConfig',
]
...

4. 定义广告数据模型类:

# /apps/contents/views.py

from django.db import models

# Create your models here.
from meiduo_mall.utils.models import BaseModel


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 self.name


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.category.name + ': ' + self.title