text: var mongoose  = require('mongoose');
  var Schema    = mongoose.Schema;
  var ObjectId  = Schema.Types.ObjectId;
  
  var PageViewSchema = new Schema({//浏览量
  	user_id: { type: String },//浏览者id(如果是登录用户)
  	user: { type: Boolean },//是否是用户
  	count: { type: Number, default: 0 },//
  	create_at: { type: Date, default: Date.now },
  	update_at: { type: Date, default: Date.now },
  });
  
  PageViewSchema.index({ create_at: -1});
  
  const PV = mongoose.model('PV', PageViewSchema);
  module.exports = PV;