三重嵌套数组 MongoDB 查询答案

【问题标题】：Triple Nested Array MongoDB Query三重嵌套数组 MongoDB 查询
【发布时间】：2015-12-18 17:22:53
【问题描述】：

我想找到正确的查询以返回 Boards 集合中成员 ID 与 1 匹配的所有 Boards。有任何接受者吗？

我的架构如下：

在“Boards”系列中，

      { name: 'Board One',
    teams: [
      { name: 'Team One',
        members: [
            { id: '1', name: 'Garrett' },
            { id: '2', name: 'Sarah' }
        ]
      },
      { name: 'Team Two',
        members: [
            { id: '1', name: 'Garrett' },
            { id: '2', name: 'Jeff' }
        ]
      }
    ]
  },`{ name: 'Board Two',
    teams: [
      { name: 'Team One',
        members: [
            { id: '1', name: 'Garrett' },
            { id: '2', name: 'Sarah' }
        ]
      },
      { name: 'Team Three',
        members: [
            { id: '1', name: 'Jim' },
            { id: '2', name: 'Samson' }
        ]
      }
    ]

我正在尝试查询数组中、对象数组中、集合中的对象。我已经尝试了以下查询的许多变体..

Boards.find({
  'teams': { 
            $elemMatch: {
                          'members' : { 
                                      $elemMatch : 
                                          { 
                                            'id' : Meteor.userId() 
                                          }  
                                      }
                        }
        }
})

我想找到正确的查询以返回 Boards 集合中成员 ID 与 1 匹配的所有 Boards。

【问题讨论】：

标签： mysql arrays mongodb collections javascript-objects

【解决方案1】：

这可能是因为您将 id 作为字符串存储在集合中吗？正如您将在下面看到的，我尝试用硬编码字符串值（带单引号或双引号）替换 Meteor.userId() 查询，例如“1”或“3”，我相信查询输出就是您要查找的内容。

> db.boards.find().pretty()
{
        "_id" : ObjectId("567443e7fba7a186bcd48bfd"),
        "name" : "Board One",
        "teams" : [
                {
                        "name" : "Team One",
                        "members" : [
                                {
                                        "id" : "1",
                                        "name" : "Garrett"
                                },
                                {
                                        "id" : "2",
                                        "name" : "Sarah"
                                }
                        ]
                },
                {
                        "name" : "Team Two",
                        "members" : [
                                {
                                        "id" : "1",
                                        "name" : "Garrett"
                                },
                                {
                                        "id" : "2",
                                        "name" : "Jeff"
                                }
                        ]
                }
        ]
}
{
        "_id" : ObjectId("5674441ffba7a186bcd48bfe"),
        "name" : "Board Two",
        "teams" : [
                {
                        "name" : "Team One",
                        "members" : [
                                {
                                        "id" : "1",
                                        "name" : "Garrett"
                                },
                                {
                                        "id" : "2",
                                        "name" : "Sarah"
                                }
                        ]
                },
                {
                        "name" : "Team Three",
                        "members" : [
                                {
                                        "id" : "1",
                                        "name" : "Jim"
                                },
                                {
                                        "id" : "2",
                                        "name" : "Samson"
                                }
                        ]
                }
        ]
}
>

> db.boards.find({
...   'teams': {
...             $elemMatch: {
...                           'members' : {
...                                       $elemMatch :
...                                           {
...                                             'id' : '1'
...                                           }
...                                       }
...                         }
...         }
... })
{ "_id" : ObjectId("567443e7fba7a186bcd48bfd"), "name" : "Board One", "teams" : [ { "name" : "Team One", "members" : [ { "id" : "1", "name" : "Garrett" }, { "id" : "2", "name" : "Sarah" } ] }, { "name" : "Team Two", "members" : [ { "id" : "1", "name" : "Garrett" }, { "id" : "2", "name" : "Jeff" } ] } ] }
{ "_id" : ObjectId("5674441ffba7a186bcd48bfe"), "name" : "Board Two", "teams" : [ { "name" : "Team One", "members" : [ { "id" : "1", "name" : "Garrett" }, { "id" : "2", "name" : "Sarah" } ] }, { "name" : "Team Three", "members" : [ { "id" : "1", "name" : "Jim" }, { "id" : "2", "name" : "Samson" } ] } ] }
>
>
> db.boards.find({
...   'teams': {
...             $elemMatch: {
...                           'members' : {
...                                       $elemMatch :
...                                           {
...                                             'id' : '3'
...                                           }
...                                       }
...                         }
...         }
... })
>
>

【讨论】：