首页 \ 问答 \ 在mongoDB中如何达到对象数组中字段“name”的值(In mongoDB how to reach to value of the field “name” in the array of objects)

在mongoDB中如何达到对象数组中字段“name”的值(In mongoDB how to reach to value of the field “name” in the array of objects)

 我需要搜索有多少人拥有一个特定的朋友（通过名称），而JSON中的每个记录都有一组朋友。 我如何能够达到mongoDB shell中对象数组中的字段“name”的值？ 也许这个领域需要在这个领域执行搜索之前索引？  
 
 
  
  "friends" : [{ "id" : 0, "name" : "Baird Fitzpatrick" }, { "id" : 1, "name" : "Karyn Benjamin" }, { "id" : 2, "name" : "Stacey Fuentes" }] 
  
 
 

I need to search how many people have a specific friend (by name) and each records in JSON have an array of friends. How can I reach to the value of the field "name" in the array of objects in mongoDB shell? Maybe this field need to be indexed before perform searches on this field? 
 
 
  
  "friends" : [{ "id" : 0, "name" : "Baird Fitzpatrick" }, { "id" : 1, "name" : "Karyn Benjamin" }, { "id" : 2, "name" : "Stacey Fuentes" }] 
  
 
 

原文：https://stackoverflow.com/questions/50335520

更新时间：2021-06-22 17:06

最满意答案

 我认为这是你所要求的全面实施。 您可以更改一些逻辑并适当调整我的示例：  
 
 
  
  <!DOCTYPE html>
<html>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<script srt="https://cdnjs.cloudflare.com/ajax/libs/angular-ui-bootstrap/2.5.0/ui-bootstrap.min.js"></script>

<body>

  <div ng-app="myApp" ng-controller="HelloCntl">

    <div ng-controller="HelloCntl">
      <select ng-model="selected" ng-options="i as i.name for i in friends"></select>
       <button class="btn btn-danger" ng-click="delete(selected)">X</button>
       <div ng-show="selected" class="alert alert-info">Name: {{selected.name}} | ID: {{selected.id}}</div>
       <br>
      <input ng-model="new_selected">
      <button class="btn btn-info" ng-click="add(new_selected)">Add</button>

    </div>

    <script>
      var app = angular.module('myApp', []);
      app.controller('HelloCntl', HelloCntl);

      function HelloCntl($scope) {
        $scope.friends = [
          {id:1,name: 'John'},
          {id:2,name: 'Mary'},
          {id:3,name: 'Mike'},
          {id:4,name: 'Adam'},
          {id:5,name: 'Julie'}
        ];
        $scope.selected = $scope.friends[0]; // initialise selection
        $scope.delete = function(x) {
          var y = $scope.friends.indexOf(x);
          $scope.friends.splice(y, 1);
        }
        var index = 6;
        $scope.add = function(x) {
          $scope.friends.push({
            id: index,
            name: x
          });
          index++;
          $scope.new_selected = '';
        }

      }
    </script>

</body>

</html> 
  
 

I think this the full implementation of what you have requested. You can change some of the logic and adjust my example appropriately: 
 
 
  
  <!DOCTYPE html>
<html>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<script srt="https://cdnjs.cloudflare.com/ajax/libs/angular-ui-bootstrap/2.5.0/ui-bootstrap.min.js"></script>

<body>

  <div ng-app="myApp" ng-controller="HelloCntl">

    <div ng-controller="HelloCntl">
      <select ng-model="selected" ng-options="i as i.name for i in friends"></select>
       <button class="btn btn-danger" ng-click="delete(selected)">X</button>
       <div ng-show="selected" class="alert alert-info">Name: {{selected.name}} | ID: {{selected.id}}</div>
       <br>
      <input ng-model="new_selected">
      <button class="btn btn-info" ng-click="add(new_selected)">Add</button>

    </div>

    <script>
      var app = angular.module('myApp', []);
      app.controller('HelloCntl', HelloCntl);

      function HelloCntl($scope) {
        $scope.friends = [
          {id:1,name: 'John'},
          {id:2,name: 'Mary'},
          {id:3,name: 'Mike'},
          {id:4,name: 'Adam'},
          {id:5,name: 'Julie'}
        ];
        $scope.selected = $scope.friends[0]; // initialise selection
        $scope.delete = function(x) {
          var y = $scope.friends.indexOf(x);
          $scope.friends.splice(y, 1);
        }
        var index = 6;
        $scope.add = function(x) {
          $scope.friends.push({
            id: index,
            name: x
          });
          index++;
          $scope.new_selected = '';
        }

      }
    </script>

</body>

</html>

在mongoDB中如何达到对象数组中字段“name”的值(In mongoDB how to reach to value of the field “name” in the array of objects)

最满意答案

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