Complete e-commerce project--(6) Commodity module (8): User browsing history

User browsing history introduction

• We record up to five browsing history product records of users, and present
• Use redis as storage

Redis data type selection (document)

• demand analysis
  • We need to save five browsing records for each user, and we need to know who the user is
• Data type selection:
  • Implemented using list type
  • Storage format : history_user_id': [sku_id_1, sku_id_2, …]

redis storage logic

• First need to remove the duplication
  • Join already stored [1,2] , insert 2 again at this time, it cannot be [2,1, 2], so use deduplication
• Save
• Intercept list:
  • There are only five data, which need to be intercepted each time, and the part exceeding the length of 5 is not needed
• Pipeline execution to improve performance efficiency

 # 保存用户浏览数据
        redis_conn = get_redis_connection('history')
        pl = redis_conn.pipeline()
        user_id = request.user.id

        # 先去重， 0 表示去除所有的相同元素
        pl.lrem('history_%s' % user_id, 0, sku_id)
        # 再存储
        pl.lpush('history_%s' % user_id, sku_id)
        # 最后截取
        pl.ltrim('history_%s' % user_id, 0, 4)
        # 执行管道
        pl.execute()

that's it. You only need to execute the query when you need it

Read data command

Very simple, it is to use redis to store browsing records.