I want to modify the result in a `schema.post('find')' middleware, but this seems impossible:
const PersonSchema = new mongoose.Schema({ name: String })
PersonSchema.post('find', function(result) {
console.log('HOOW: Post Find', result)
result.team("Real Madrid")
return result
})
const Person = mongoose.model('Person', PersonSchema)
Whenever I try to perform a find query, the console.log statement is executed but, the team field never gets added.
How can I add this field to my result?
NOTE:
My real code is a bit more complex, I need to make some queries to the database and add those results to the result of the find query.
your problem is in result.team("Real Madrid")
change to
result.team="Real Madrid"
or
result['team']="Real Madrid" (Quotes are required)
try this
PersonSchema.post('find', function(result) {
console.log('HOOW: Post Find', result)
result.team="Real Madrid"
return result
})
To add additional field to documents returned from query, you may use lean():
Person.find({...}).lean();
And because result of find() method is an array so you need to loop through it and add field to each element:
PersonSchema.post('find', function(result) {
console.log('HOOW: Post Find', result)
result.forEach(val => val.team="Real Madrid");
return result
})
You should use like this
PersonSchema.post('find', function(result) {
result= result.toObject();
console.log('HOOW: Post Find', result)
result.team("Real Madrid")
return result
})
Related
I am sending a query to mongoDB using mongoose. The collection is named Step. I want the result of this query to be an array of _id values, one per step. Currently I am getting all of the step objects in their entirety, because req.query isn't defined in this case.
service:
this.getSteps = function() {
return $http({
method: 'GET',
url: '/api/step'
})
.then(function(response) {
return response.data;
});
};
controller:
readStep: function (req, res) {
Step.find(req.query, function(err, result) {
if (err) {
res.status(500).send(err);
}
res.status(200).send(result);
});
}
Set the second parameter of the find query to '_id' to retrieve only the _id of the objects.
Step.find(req.query, '_id', function(err, result) {
This will return data like this:
[{_id: 123}, {_id: 234}]
If you want to get an array of the Step ids on their own, use the javascript map function like so
result = result.map(function(doc) {
return doc._id;
});
which will give you an array like this:
[123, 234]
You'll need to use query.select, something like as shown below:
Step.find(query).select({ "_id": 1}).then(....);
I'm not able to type much because I'm responding from my handheld.
Hope this help!
I am trying to fetch all the records but with selected fields, I have tried the following ways but none works:
Post.find(
{
where: {},
select: ['title']
}
);
Post.find(
{},
{
fields: {
title: 1
}
}
);
As this answer points out, the fields param "WILL work as long as you pass other params with it such as limit or order."
Alternatively, if you want this throughout your application, you could define a custom toJSON function for your model, under attributes. If not, you could still define it under some other (e.g. filter) and use map to return the custom objects instead of the default model. Remember to take care of the control flow while using map though. Use async/promises/raw logic to avoid returning before all objects are processed.
The issue has been resolved in sails-mongo latest version:
https://github.com/balderdashy/waterline/issues/1098
Thanks
I've played with trying to get above answer to use limit or order to kick in the projection to no avail.
I did see this in the docs located here:
http://sailsjs.org/documentation/reference/waterline-orm/models/native
With an out of the box solution for exactly what you're doing (pasted here for ease of use).
Pet.native(function(err, collection) {
if (err) return res.serverError(err);
collection.find({}, {
name: true
}).toArray(function (err, results) {
if (err) return res.serverError(err);
return res.ok(results);
});
});
Swap out the response base things and change Pet to Post and, this ought to work in the sails console:
Post.native(function(err, collection) {
if (err) throw new Error(err);
collection.find({}, {
title: true
}).toArray(function (err, results) {
if (err) throw new Error(err);
console.log(results);
});
});
You'll still get the _id field, and if you don't want that then hit the Mongo docs on not getting those hint(title: true, _id: false)hint
Hope this helps!
All the examples I have seen for MongoDb & Mongoskin for update, have individual properties being updated, like so:
// this works when I specify the properties
db.collection('User').update({_id: mongoskin.helper.toObjectID(user._id)},
{'$set':{displayName:user.displayName}}, function(err, result) {
if (err) throw err;
if (result){ res.send(result)}
});
But what if I wanted the whole object/document to be updated instead:
// this does not appear to work
db.collection('User').update({_id: mongoskin.helper.toObjectID(user._id)}, {'$set':user},
function(err, result){
// do something
}
It returns the error:
// It appears Mongo does not like the _id as part of the update
MongoError: After applying the update to the document {_id: ObjectId('.....
To overcome this issue, this is what I had to do to make things work:
function (req, res) {
var userId = req.body.user._id
var user = req.body.user;
delete user._id;
db.collection('User').update({_id: mongoskin.helper.toObjectID(userId)},
{'$set':user}, function(err, result) {
if (err) throw err;
console.log('result: ' + result)
if (result){ res.send(result)}
});
})
It there a more elegant way of updating the whole document, instead of hacking it with:
delete user._id
If you want to update the whole object, you do not need a $set. I am not aware of mongoskin, but in shell you would do something like:
var userObj = {
_id: <something>
...
};
db.user.update({_id: user._id}, user);
Which I think can be translated in your mongoskin in the following way.
db.collection('User').update({_id: user._id}, user, function(){...})
But here is the problem. You can not update _id of the element in Mongo. And this is what your error tells you. So you can remove the _id from your user object and have it separately. Search by this separate _id and update with a user object without _id.
I have a fairly straight forward method below to update a document based on its ObjectId. It does not return an error but it fails to make the required updates to the document. I think it is failing because, according to my research, findByIdAndUpdate() takes only plain Javascript whereas job._id is an ObjectId from the document that I want to update. Can someone tell me how to make this work correctly?
function handleEncoderResponse(xmlResponse, job) {
var r = et.parse(xmlResponse);
var mediaID = r.findtext('./MediaID');
var message = r.findtext('./message');
EncodingJob = mongoose.model('EncodingJob');
EncodingJob.findByIdAndUpdate( job._id, {
"MediaID": mediaID,
"Status": message
}, function(err, result) {
if (err) console.log(err);
console.log(result);
});
}
Edit: Per this question Mongoose update document Fail with findByIdAndUpdate
I also tried the following code to no avail.
job.MediaID = mediaID;
job.Status = message;
job.save(function(err, res) {
if(err) console.log(err);
});
This approach yields the issue. It does not update the document and it does not return an error.
As it turns out, my mistake was forgetting to define MediaID and Status in the Schema as follows:
var encodingJobSchema = new mongoose.Schema({
...
MediaID: String,
Status: String
});
I have a number of records stored in a MongoDB I'm trying to output them to the browser window by way of a Node.JS http server. I think I'm a good portion of the way along but I'm missing a few little things that are keeping it from actually working.
The code below uses node-mongo-native to connect to the database.
If there is anyone around who can help me make those last few connections with working in node I'd really appreciate it. To be fair, I'm sure this is just the start.
var sys = require("sys");
var test = require("assert");
var http = require('http');
var Db = require('../lib/mongodb').Db,
Connection = require('../lib/mongodb').Connection,
Server = require('../lib/mongodb').Server,
//BSON = require('../lib/mongodb').BSONPure;
BSON = require('../lib/mongodb').BSONNative;
var host = process.env['MONGO_NODE_DRIVER_HOST'] != null ? process.env['MONGO_NODE_DRIVER_HOST'] : 'localhost';
var port = process.env['MONGO_NODE_DRIVER_PORT'] != null ? process.env['MONGO_NODE_DRIVER_PORT'] : Connection.DEFAULT_PORT;
sys.puts("Connecting to " + host + ":" + port);
function PutItem(err, item){
var result = "";
if(item != null) {
for (key in item) {
result += key + '=' + item[key];
}
}
// sys.puts(sys.inspect(item)) // debug output
return result;
}
function ReadTest(){
var db = new Db('mydb', new Server(host, port, {}), {native_parser:true});
var result = "";
db.open(function (err, db) {
db.collection('test', function(err, collection) {
collection.find(function (err, cursor){
cursor.each( function (err, item) {
result += PutItem(err, item);
});
});
});
});
return result;
}
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end("foo"+ReadTest());
}).listen(8124);
console.log('Server running on 8124');
Sources:
- mongo connectivity code:
https://github.com/christkv/node-mongodb-native/blob/master/examples/simple.js
- node. http code: nodejs.org
EDIT CORRECTED CODE
Thanks to Mic below who got me rolling in the right direction. For anyone interested, the corrected solution is here:
function ReadTest(res){
var db = new Db('mydb', new Server(host, port, {}), {native_parser:true});
var result = "";
res.write("in readtest\n");
db.open(function (err, db) {
res.write("now open\n");
db.collection('test', function(err, collection) {
res.write("in collection\n");
collection.find(function (err, cursor){
res.write("found\n");
cursor.each( function (err, item) {
res.write("now open\n");
var x = PutItem(err, item);
sys.puts(x);
res.write(x);
if (item == null) {
res.end('foo');
}
});
});
});
});
}
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.write("start\n");
ReadTest(res);
}).listen(8124);
console.log('Server running on 8124');
My guess is that you are returning result, writing the response, and closing the connection before anything is fetched from the db.
One solution would be to pass the response object to where you actually need it, something like:
function readTest(res) {
db.open(function (err, db) {
db.collection('test', function(err, collection) {
collection.find(function (err, cursor) {
res.writeHead(200, {'Content-type' : 'text/plain'});
cursor.each( function (err, item) { res.write(item); });
res.end();
...
Of course, you should also handle errors and try to avoid nesting too many levels, but that's a different discussion.
Instead of writing all the low-level Mongodb access code, you might want to try a simple library like mongous so that you can focus on your data, not on MongoDB quirks.
You might want to try mongoskin too.
Reading documents
To apply specific value filters, we can pass specific values to the find() command. Here is a SQL query:
SELECT * FROM Table1 WHERE name = 'ABC'
which is equivalent to the following in MongoDB (notice Collection1 for Table1):
db.Collection1.find({name: 'ABC'})
We can chain count() to get the number of results, pretty() to get a readable result. The results can be further narrowed by adding additional parameters:
db.Collection1.find({name: 'ABC', rollNo: 5})
It's important to notice that these filters are ANDed together, by default. To apply an OR filter, we need to use $or. These filters will be specified depending upon the structure of the document. Ex: for object attribute name for an object school, we need to specify filter like "school.name" = 'AUHS'
We're using here the DOT notation, by trying to access a nested field name of a field school. Also notice that the filters are quoted, without which we'll get syntax errors.
Equality matches on arrays can be performed:
on the entire arrays
based on any element
based on a specific element
more complex matches using operators
In the below query:
db.Collection1.find({name: ['ABC','XYZ']})
MongoDB is going to identify documents by an exact match to an array of one or more values. Now for these types of queries, the order of elements matters, meaning that we will only match documents that have ABC followed by XYZ and those are the only 2 elements of the array name
{name:["ABC","GHI","XYZ"]},
{name:["DEF","ABC","XYZ"]}
In the above document, let's say that we need to get all the documnts where ABC is the first element. So, we'll use the below filter:
db.Schools.find({'name.0': 'ABC' })