查询以显示子文档不工作
我相当新mongoose，我想写一个查询，只是返回我的主文档中的一个子文档。
我的文档结构是这样的：
PROFILE - CONTACTS [ARRAY] 我已经写了以下端点来返回一个联系人，我通过configuration文件ID和子文档的ID：
“/：owerId / getcontact /：使用ContactID”
我的Expressfunction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); }) }) })
但是这个代码返回整个configuration文件。
当我试图通过身份证得到同样的事情。 这里是我的代码，下面是返回的整个configuration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": [] }
mongoose子文件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子文档 。
另一条路线是通过聚合框架，您可以使用$match ， $arrayElemAt和$filter运算符来返回所需的数据。
考虑在您的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); }) })