const path = require('path')
 const mongoose = require('mongoose')
 const cities = require('./cities')
 const Campground = require('../views/models/campground')
 const {descriptors,places} = require('./seedhelpers')

 mongoose.connect('mongodb://localhost:27017/yelp-camp', {
      useNewUrlParser:true,
      //useCreateIndex:true,
      //useFindAndModify:true,
      useUnifiedTopology:true
 })

 db = mongoose.connection;
 db.on("error", console.error.bind(console, "connection ERROR"));
 db.once("open", ()=>{
 console.log("Database connection open")
 })

 const sample = array => array[Math.floor(Math.random() * array.length )]

 const seedDB =  async()=>{
     await Campground.deleteMany({});
     for(let i=0; i<50; i++){
     const random1000 = Math.floor(Math.random() * 1000)
     const price = Math.floor(Math.random()*20)*10
     const camp = new Campground({
         author:'63dbcd28bd0379985929400c',
         location: `${cities[random1000].city}, ${cities[random1000].state} `, 
         title: `${sample(descriptors)} ${sample(places)}`,
         image:'https://source.unsplash.com/collection/483251',
         description:"Lorem ipsum, dolor sit amet consectetur adipisicing elit. Delectus labore magnam          reiciendis ex corrupti, nobis, obcaecati alias laboriosam voluptatum, cumque dignissimos accusamus? Voluptatibus accusamus voluptatum nulla vel doloribus, delectus voluptatem?",
         price
         })
         await camp.save()
     }
}

 seedDB().then(()=>{
 mongoose.connection.close();
})

显示10秒后缓冲。但我在这里等待。我想删除所有的营地，并使一套新的营地每次我运行的文件。所以我给了它。