一、SPU、SKU和商品数据库表设计

在电商项目里面为了准确的描述商品的区别，我们抽象出来两个概念，Spu和Sku这两个概念。

1.SPU

SPU(Standard Product Unit)：标准化产品单元。是商品信息聚合的最小单位，是一组可复用、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。通俗点讲，属性值、特性相同的商品就可以称为一个SPU。

2.SKU

SKU=Stock Keeping Unit（库存量单位）。即库存进出计量的基本单元，可以是以件，盒，托盘等为单位。

3.数据库设计ER图

4.模型类设计

from django.db import models
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', 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 self.name


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 self.name


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 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 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 self.name


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 = models.ImageField(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 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' % (self.spu.name, self.name)


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.spec.name, self.option.value)


class GoodsVisitCount(BaseModel):
    """统计分类商品访问量模型类"""
    category = models.ForeignKey(GoodsCategory, on_delete=models.CASCADE, verbose_name='商品分类')
    count = models.IntegerField(verbose_name='访问量', default=0)
    date = models.DateField(auto_now_add=True, verbose_name='统计日期')

    class Meta:
        db_table = 'tb_goods_visit'
        verbose_name = '统计分类商品访问量'
        verbose_name_plural = verbose_name

二、首页广告数据库表设计

1.数据库设计ER图

2.模型类设计

from django.db import models
from 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 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

总结

商品数据库涉及要细分不变项和可变项的设计，一对一，多对多，一对多关联要尽可能细分，对于不确定的信息可以有json形式存储。对于访问量特别大的页面可以进行mongodb存储，mongodb对于存储文档数据库是个很好的选择，库存秒杀的情况redis和mq消息队列也是必不可少，幂函数等等。