我使用Nodejs, Hapijs和Mongoose。
我有一个模式和模型如下。
var schema = {
name: {
type: String,
required: true
},
lectures: {}
};
var mongooseSchema = new mongoose.Schema(schema, {
collection: "Users"
});
mongoose.model("Users", mongooseSchema);
出于某种原因,我需要保持"讲课"。
保存/创建文档时,我创建了一个嵌套属性lectures.physics。topic[],其中topic为数组。
现在,我正在尝试添加/推送一个新对象到"lectures.physics"。使用$addToSet或$push.
userModel.findByIdAndUpdateAsync(user._id, {
$addToSet: {
"lectures.physics.topic": {
"name": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
}
}
});
但是文档没有得到更新。我也试过使用$push。毫无效果。有什么问题吗?
我尝试了另一种方法使用mongoclient,直接更新数据库。它的工作,请找到下面的代码工作
db.collection("Users").update({
"_id": user._id
}, {
$addToSet: {
"lectures.physics.topic": {
"name": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
}
}
}, function(err, result) {
if (err) {
console.log("Superman!");
console.log(err);
return;
}
console.log(result);
});
我必须在每次命中请求时启动mongo客户端。这不是一个可行的解决方案。
Mongoose失去了自动检测和保存对混合类型所做更改的能力,因此您需要通过调用文档的 .markModified(path)
方法来"告诉"它混合类型的值已经更改,并将路径传递给您刚刚更改的混合类型:
doc.mixed.type = 'changed';
doc.markModified('mixed.type');
doc.save() // changes to mixed.type are now persisted
在您的情况下,您可以使用 findById()
方法通过在主题数组上调用 addToSet()
方法来进行更改,然后触发 save()
方法来持久化更改:
userModel.findById(user._id, function (err, doc){
var item = {
"name": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
};
doc.lectures.physics.topic.addToSet(item);
doc.markModified('lectures');
doc.save() // changes to lectures are now persisted
});
我认为这是"bug"。Mongoose显然是在做错误的事情,这可以从后面的日志中得到证明。但是这里有一个清单,从本机驱动程序调用.findOneAndUpdate()
与您正在尝试做的相同的更新:
var async = require('async'),
mongoose = require('mongoose'),
Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/school');
mongoose.set('debug',true);
var userSchema = new Schema({
name: {
type: String,
required: true
},
lectures: { type: Schema.Types.Mixed }
});
var User = mongoose.model( "User", userSchema );
function logger(data) {
return JSON.stringify(data, undefined, 2);
}
async.waterfall(
[
function(callback) {
User.remove({},function(err) {
callback(err);
});
},
function(callback) {
console.log("here");
var user = new User({ "name": "bob" });
user.save(function(err,user) {
callback(err,user);
});
},
function(user,callback) {
console.log("Saved: %s", logger(user));
User.collection.findOneAndUpdate(
{ "_id": user._id },
{
"$addToSet": {
"lectures.physics.topic": {
"name": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
}
}
},
{ "returnOriginal": false },
function(err,user) {
callback(err,user);
}
);
}
],
function(err,user) {
if (err) throw err;
console.log("Modified: %s", logger(user));
mongoose.disconnect();
}
);
这样做的结果是:
Saved: {
"__v": 0,
"name": "bob",
"_id": "55cda1f5b5ee8b870e2f53bd"
}
Modified: {
"lastErrorObject": {
"updatedExisting": true,
"n": 1
},
"value": {
"_id": "55cda1f5b5ee8b870e2f53bd",
"name": "bob",
"__v": 0,
"lectures": {
"physics": {
"topic": [
{
"name": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
}
]
}
}
},
"ok": 1
}
这里需要小心,因为本机驱动程序方法不像猫鼬方法那样知道连接状态。所以你需要确保一个连接是由之前触发的"mongoose"方法建立的,或者像这样将你的应用程序包装在一个连接事件中:
mongoose.connection.on("connect",function(err) {
// start app in here
});
至于"bug",请查看清单中的日志输出:
var async = require('async'),
mongoose = require('mongoose'),
Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/school');
mongoose.set('debug',true);
var userSchema = new Schema({
name: {
type: String,
required: true
},
lectures: { type: Schema.Types.Mixed }
});
var User = mongoose.model( "User", userSchema );
function logger(data) {
return JSON.stringify(data, undefined, 2);
}
async.waterfall(
[
function(callback) {
User.remove({},function(err) {
callback(err);
});
},
function(callback) {
console.log("here");
var user = new User({ "name": "bob" });
user.save(function(err,user) {
callback(err,user);
});
},
function(user,callback) {
console.log("Saved: %s", logger(user));
User.findByIdAndUpdate(
user._id,
{
"$addToSet": {
"lectures.physics.topic": {
"name": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
}
}
},
{ "new": true },
function(err,user) {
callback(err,user);
}
);
}
],
function(err,user) {
if (err) throw err;
console.log("Modified: %s", logger(user));
mongoose.disconnect();
}
);
和使用mongoose日志记录的日志输出:
Mongoose: users.remove({}) {}
here
Mongoose: users.insert({ name: 'bob', _id: ObjectId("55cda2d2462283c90ea3f1ad"), __v: 0 })
Saved: {
"__v": 0,
"name": "bob",
"_id": "55cda2d2462283c90ea3f1ad"
}
Mongoose: users.findOne({ _id: ObjectId("55cda2d2462283c90ea3f1ad") }) { new: true, fields: undefined }
Modified: {
"_id": "55cda2d2462283c90ea3f1ad",
"name": "bob",
"__v": 0
}
所以在真正的"什么鬼?"样式,那里有一个调用.findOne()
?我问的不是这个。此外,数据库中当然不会因为错误调用而改变任何内容。所以这里的{ "new": true }
也是多余的。
这发生在"混合"模式类型的所有级别。
我个人不会像这样嵌套在"对象"中,只是让你的"对象键"作为附加属性的标准数组的一部分。MongoDB和mongoose都更喜欢这种结构,而且用这种结构查询信息要容易得多。var async = require('async'),
mongoose = require('mongoose'),
Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/school');
mongoose.set('debug',true);
var lectureSchema = new Schema({
"subject": String,
"topic": String,
"day": String,
"faculty": String
});
var userSchema = new Schema({
name: {
type: String,
required: true
},
lectures: [lectureSchema]
});
var User = mongoose.model( "User", userSchema );
function logger(data) {
return JSON.stringify(data, undefined, 2);
}
async.waterfall(
[
function(callback) {
User.remove({},function(err) {
callback(err);
});
},
function(callback) {
console.log("here");
var user = new User({ "name": "bob" });
user.save(function(err,user) {
callback(err,user);
});
},
function(user,callback) {
console.log("Saved: %s", logger(user));
User.findByIdAndUpdate(
user._id,
{
"$addToSet": {
"lectures": {
"subject": "physics",
"topic": "Fluid Mechanics",
"day": "Monday",
"faculty": "Nancy Wagner"
}
}
},
{ "new": true },
function(err,user) {
callback(err,user);
}
);
}
],
function(err,user) {
if (err) throw err;
console.log("Modified: %s", logger(user));
mongoose.disconnect();
}
);
输出:Mongoose: users.remove({}) {}
here
Mongoose: users.insert({ name: 'bob', _id: ObjectId("55cda4dc40f2a8fb0e5cdf8b"), lectures: [], __v: 0 })
Saved: {
"__v": 0,
"name": "bob",
"_id": "55cda4dc40f2a8fb0e5cdf8b",
"lectures": []
}
Mongoose: users.findAndModify({ _id: ObjectId("55cda4dc40f2a8fb0e5cdf8b") }) [] { '$addToSet': { lectures: { faculty: 'Nancy Wagner', day: 'Monday', topic: 'Fluid Mechanics', subject: 'physics', _id: ObjectId("55cda4dc40f2a8fb0e5cdf8c") } } } { new: true, upsert: false, remove: false }
Modified: {
"_id": "55cda4dc40f2a8fb0e5cdf8b",
"name": "bob",
"__v": 0,
"lectures": [
{
"faculty": "Nancy Wagner",
"day": "Monday",
"topic": "Fluid Mechanics",
"subject": "physics",
"_id": "55cda4dc40f2a8fb0e5cdf8c"
}
]
}
这很好,你不需要挖掘原生方法来让它工作。
数组的属性使得查询和过滤变得更加容易,以及跨数据的"聚合"信息,对于所有这些MongoDB喜欢"严格路径"来引用所有信息。否则你就只能区分"特定的键",如果没有提到每一个可能的"键组合",这些键就不能被索引或真正搜索。
像这样的属性是一个更好的方法。这里没有bug