Javascript 如何从Mongo数据库中获取标记的位置并在Google地图脚本上显示？|平均堆栈

我在大学里做最后一年的项目，已经和这个问题斗争了大约一个月了。任何帮助都将不胜感激

我正在进行的一个平均堆栈项目包括GoogleMapsAPI，我必须在其中显示一些对象在地图上的位置。对象的纬度和经度存储在数据库中。我们现在要做的是从数据库中获取对象的纬度和经度，并将标记放在其位置！我可以通过硬编码标记的lat和long来手动添加标记，但无法通过从后端获取数据来显示标记！我还添加了一个功能，当用户右键单击地图时，会在该位置放置一个标记

此组件的所有代码附在下面：

import { Component, OnInit } from '@angular/core';
import { DataService } from '../../data.service';

declare var getContext: any;
declare var google: any;
declare var MarkerClusterer:any;
var markerArray = [];

@Component({
    selector: 'dashboard-cmp',
    moduleId: module.id,
    templateUrl: 'dashboard.component.html'
})

export class DashboardComponent implements OnInit{

  // public promos;
  
  constructor(private _data:DataService){}

  ngOnInit(){
    // this.getpromo();
  }
  
//   getpromo(){
//     this._data.doGET().subscribe(
//         data => { this.promos = data},
//         // lat => {this.promos.latitude = lat},
//         // long => {this.promos.longitude = long}
//         err => console.error(err),
//         () => console.log('done loading Promos')
        
//     );
//   }
} 

  // MAPS

  // In the following example, markers appear when the user clicks on the map.
  // Each marker is labeled with a single alphabetical character.

  var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
  var labelIndex = 0;

  function initialize() {
    var islamabad = { lat:33.6844, lng: 73.0479 };
    var map = new google.maps.Map(document.getElementById('map'), {
      zoom: 12,
      center: islamabad
    });

  // Add a marker at the center of the map.
    addMarker(islamabad, map);
    
  var image="https://img.icons8.com/emoji/48/000000/coin-emoji.png";

    function addMarker(location, map) {
      // Add the marker at the clicked location, and add the next-available label
      // from the array of alphabetical characters.
      var marker = new google.maps.Marker({
        position: location,
        label: labels[labelIndex++ % labels.length],
        map: map,
        icon: image
      });
      var markerCluster = new MarkerClusterer(map, markerArray,
        {imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m'});
    
  }
}

google.maps.event.addDomListener(window, 'load', initialize);