Question

我对mongoose相当新，我正在尝试编写一个只返回主文档中的子文档的查询。

我的文档结构如下：

PROFILE
    - CONTACTS [ARRAY]

我已经编写了以下端点来返回一个联系人，我在其中传递了个人资料ID和子文档的ID：

＆＃34; /：owerId / getcontact /：使用ContactID＆＃34;

My Express功能代码如下所示：

router.route('/:ownerId/getcontact/:contactId')

    .get(function(req, res){
      Profile.findOne({'owner_id':req.params.ownerId}).then(function(err, profile){
        if(err)
          res.send(err);

        profile.findOne({'_id':req.params.contactId}).then(function(err, contact){
          if(err)
            res.send(err);
          res.json(contact);
        })

      })
    })

但是这段代码会返回整个个人资料。

当我尝试通过ID获取时它会做同样的事情。这是我的代码，下面是返回的整个配置文件：

router.route('/:ownerId/getcontact/:contactId')

.get(function(req, res){
  Profile.findById(req.params.ownerId).then(function(err, profile){
    if(err)
      res.send(err);

      var data = profile.contacts.id(req.params.contactId);

    res.json(data);

  })
})





{
  "_id": "5886e3692ca4542c453431ee",
  "initial": "u",
  "last_name": "randal",
  "first_name": "chris",
  "owner_id": "5886e32c2ca4542c453431ed",
  "__v": 1,
  "contacts": [
    {
      "last_name": "Eltoro",
      "first_name": "Peter",
      "_id": "5886e3f5a219472cac886a9f",
      "businesses": [],
      "addresses": [],
      "phones": [
        {
          "phone_type": "mobile",
          "phone_number": "555-555-999",
          "_id": "5886e3f5a219472cac886aa2"
        },
        {
          "phone_type": "home",
          "phone_number": "999-876-000",
          "_id": "5886e3f5a219472cac886aa1"
        }
      ],
      "emails": [
        {
          "email_address": "tim@time.com",
          "_id": "5886e3f5a219472cac886aa0"
        }
      ]
    },
    {
      "college": "University of WA",
      "highschool": "Kalaheo",
      "birthday": "1990-12-22T08:00:00.000Z",
      "last_name": "Smith",
      "first_name": "Suzanne",
      "_id": "5886fb7fac288c2e31eabe0a",
      "businesses": [],
      "addresses": [
        {
          "zip": "98777",
          "state": "WA",
          "city": "Seattle",
          "address_2": "Apt 234",
          "address": "124 194th St. SW",
          "_id": "5886fb7fac288c2e31eabe0e"
        }
      ],
      "phones": [
        {
          "phone_type": "mobile",
          "phone_number": "206-899-9898",
          "_id": "5886fb7fac288c2e31eabe0d"
        },
        {
          "phone_type": "home",
          "phone_number": "206-789-0987",
          "_id": "5886fb7fac288c2e31eabe0c"
        }
      ],
      "emails": [
        {
          "email_type": "personal",
          "email_address": "suzanne@smith.com",
          "_id": "5886fb7fac288c2e31eabe0b"
        }
      ]
    },
    {
      "last_name": "Alabaster",
      "first_name": "Cindy",
      "_id": "5888b0bd3c025e54476828d9",
      "businesses": [],
      "addresses": [],
      "phones": [
        {
          "phone_type": "home",
          "phone_number": "999-999-0909",
          "_id": "5888b0bd3c025e54476828dc"
        },
        {
          "phone_type": "home",
          "phone_number": "000-000-0000",
          "_id": "5888b0bd3c025e54476828db"
        }
      ],
      "emails": [
        {
          "email_address": "Some@them.com",
          "_id": "5888b0bd3c025e54476828da"
        }
      ]
    }
  ],
  "businesses": [],
  "addresses": [],
  "phones": [
    {
      "phone_number": "999-999-9999",
      "phone_type": "mobile",
      "_id": "5886e37f2ca4542c453431ef"
    }
  ],
  "emails": []
}

Answer 1

Mongoose子文档有特殊的方法来检索它们：

router
  .route('/:ownerId/getcontact/:contactId')
    .get(function(req, res) {
      Profile.findOne({ owner_id: req.params.ownerId }, function(err, profile) {
        if ( err ) {
          res.send(err);
        }
        var contact = profile.contacts.id(req.params.contactId);
        res.json(contact);
      });
    });

请参阅Mongoose Sub Documents。

Answer 2

另一条路线是通过聚合框架，您可以使用 $match ， $arrayElemAt 和 $filter < / strong>运算符返回您想要的数据。

考虑在API端点实现中运行以下聚合操作：

router.route('/:ownerId/getcontact/:contactId') .get(function(req, res){ var ownerId = mongoose.Schema.Types.ObjectId(req.params.ownerId), contactId = mongoose.Schema.Types.ObjectId(req.params.contactId); Profile.aggregate([ { "$match": { "owner_id": ownerId } }, { "$project": { "contact": { "$arrayElemAt": [ { "$filter": { "input": "$contacts", "as": "contact", "cond": { "$eq": ["$$contact._id", contactId] } } }, 0 ] } } } ]).exec(function(err, profile){ if(err) res.send(err); res.json(profile[0].contact); }) })

查询显示子文档无法正常工作

2 个答案: