我需要从数据库的地图中保存一个值答案

【问题标题】：I need to save a value from a map on database我需要从数据库的地图中保存一个值
【发布时间】：2020-11-10 00:20:00
【问题描述】：

好吧，我需要帮助才能将 const 映射中的值保存到数据库中。我在一些论坛上进行了搜索，阅读了 MongoDB 文档，但我一无所获，那么，如何从 mongodb 上的地图（单独）中保存一个值？

const mongoose = require('mongoose');
const Members = require('../models/Members');
const { DATABASE } = require('../../config/config.json');

module.exports.run = async (Client, message, args) => {
  const ServerCache = Client.guilds.cache.get('719394166483845210');

  const cacheID = ServerCache.members.cache.map(member => member.user.id);
  const cacheTag = ServerCache.members.cache.map(member => member.user.tag);
  const cacheIsBot = ServerCache.members.cache.map(member => member.user.bot);

  // Database connection
  mongoose.connect(DATABASE.URL, DATABASE.OPTIONS);

  for (var i = 0; i < cacheID.length; i++) {
    if (cacheIsBot[i]) {
      console.log("Este usuário é um BOT, então foi ignorado!");
    } else {

      Members.find({ 'dsID': cacheID[i] }, (err, discordID) => {
        if (discordID.length >= 1) {
          console.log("Este usuário já está cadastrado");
          return;
        }

        const MembersDocument = new Members({
          dsID: cacheID[i],
          dsTag: cacheTag[i]
        });

        MembersDocument.save();
      });
    }
  }
}

【问题讨论】：

标签： javascript node.js mongodb mongoose discord.js

【解决方案1】：

您在 for 循环中使用了异步函数。所以循环在函数响应之前结束。您可以为此使用异步模块。

const mongoose = require('mongoose');
const Members = require('../models/Members');
const async = require("async");
const { DATABASE } = require('../../config/config.json');

module.exports.run = async (Client, message, args) => {
  const ServerCache = Client.guilds.cache.get('719394166483845210');

  const dsID = ServerCache.members.cache.map(member => member.user.id);
  const dsTag = ServerCache.members.cache.map(member => member.user.tag);
  const dsIsBot = ServerCache.members.cache.map(member => member.user.bot);

  // Database connection
  mongoose.connect(DATABASE.URL, DATABASE.OPTIONS);

  async.eachSeries(dsID, function (dsIDItem, nextItem) {
      let i = dsID.indexOf(dsIDItem); // for dsTag and dsIsBot index.
      if (dsIsBot[i]) {
      console.log("Este usuário é um BOT, então foi ignorado!")
    } else {
      Members.find({ 'dsID': dsIDItem }, (err, discordID) => {
        if (discordID.length >= 1) { return; }

        const MembersDocument = new Members({
          dsID: dsIDItem, // <-- I tried to use [i] to save that map value with for
          dsTag: dsTag[i],
        });

        MembersDocument.save(function(){ nextItem(); });
      });
    }
  }, function(err) {
      // end loop
  })
}

【讨论】：

【解决方案2】：

我用其他方式做了，添加一个新变量来引用地图项：

const dsID = cacheID[i];
const dsTag = cacheTag[i];

在新文档上

const MembersDocument = new Members({
    dsID: dsID,
    dsTag: dsTag,
});

对我来说很好。

【讨论】：