I would like to remove dynamically a field from a mongoose document.
What I have tried:
I am using
$unset
and when I type the value
"cars.BMW"
it works. But when I want to pass a parameter, which will be a car brand and then to unset it. I tried
{$unset: {"cars."+brand: " "}}
but the plus sign is unexpected.
You can use destructuring and Template literals:
{$unset: {[`cars.${brand}`]: " "}}
Dot notation doesn't work like that. In js, you would use bracket notation to create a property dynamically from a string.
exports.deleteBrand = function(req, res){
var brand = req.params.brand;
var query = {};
query["cars." + brand] = "";
Text.update(
{key: req.params.key},
{$unset: query},
function(err){ if(err) res.send(err);
res.json({message: "Car deleted!"});
});
}
The query variable here translates to: {"cars.bmw": ""} if the brand is "bmw".
EDIT: Edited to match the method by op.
You can use $unset to remove feld, here is the example:
User.findOneAndUpdate(
{confirmationKey: req.params.key},
{isConfirmed: true, $unset: { confirmationKey: ""}}, {}, (err, doc) => {
if (err) {
res.status(HttpStatus.BAD_REQUEST).send(StatusGen.getError(err))
} else {
console.log('user = ' + JSON.stringify(doc))
res.send(StatusGen.getSuccess('confirmed'))
}
})
Now field confirmationKey is is deleted.
Related
I'm sending the following object for mongoose to update:
{
"name" : "John",
"fruit" : "5a3d678d9b1549979d81c6ba" // this is an objectID
}
and the method:
db_user.findByIdAndUpdate(req.params.id, req.body).then(function(user, err) {
res.send(user);
});
This works fine if I replace the fruit with another fruitID which is what I'm trying to update.
However, if I send an object with no fruit, it won't remove the fruit field from the user document. Such as:
{
"name" : "John"
}
It will update whatever name I pass, but it won't remove the fruit field. Why?
Also: I can't be checking for each field that I'm sending or not and do an $unset for each accordingly, because I'm sending a lot of fields. I just want Mongoose to override the old document with the new one.
I know this is a little complicated / ugly and I'm sure there is an easier way but this should work if you want to update on specific thing and not have it fill the other values in blank.
function updateItem(req, res) {
function GetObjectFromKeyValuePairs(pairs) {
var tmp = {};
for(var key in pairs)
if(key[0] !== "_")
if(pairs[key].length !== 0)
tmp[`${key}`] = `${pairs[key]}`;
return tmp;
}
let updateOnlyChangedVals = GetObjectFromKeyValuePairs(req.body);
DB.Item.update({_id: req.params.id}, {$set: updateOnlyChangedVals},{new:true}, (err, uItem) => {
if (err) { return console.log("index error: " + err); }
res.json(uItem);
});
}
I'm using the Mongoose Library for accessing MongoDB with node.js
Is there a way to remove a key from a document? i.e. not just set the value to null, but remove it?
User.findOne({}, function(err, user){
//correctly sets the key to null... but it's still present in the document
user.key_to_delete = null;
// doesn't seem to have any effect
delete user.key_to_delete;
user.save();
});
In early versions, you would have needed to drop down the node-mongodb-native driver. Each model has a collection object that contains all the methods that node-mongodb-native offers. So you can do the action in question by this:
User.collection.update({_id: user._id}, {$unset: {field: 1 }});
Since version 2.0 you can do:
User.update({_id: user._id}, {$unset: {field: 1 }}, callback);
And since version 2.4, if you have an instance of a model already you can do:
doc.field = undefined;
doc.save(callback);
You'll want to do this:
User.findOne({}, function(err, user){
user.key_to_delete = undefined;
user.save();
});
I use mongoose and using any of the above functions did me the requirement. The function compiles error free but the field would still remain.
user.set('key_to_delete', undefined, {strict: false} );
did the trick for me.
At mongo syntax to delete some key you need do following:
{ $unset : { field : 1} }
Seems at Mongoose the same.
Edit
Check this example.
Try:
User.findOne({}, function(err, user){
// user.key_to_delete = null; X
`user.key_to_delete = undefined;`
delete user.key_to_delete;
user.save();
});
if you want to remove a key from collection try this method.
db.getCollection('myDatabaseTestCollectionName').update({"FieldToDelete": {$exists: true}}, {$unset:{"FieldToDelete":1}}, false, true);
Could this be a side problem like using
function (user)
instead of
function(err, user)
for the find's callback ? Just trying to help with this as I already had the case.
Mongoose document is NOT a plain javascript object and that's why you can't use delete operator.(Or unset from 'lodash' library).
Your options are to set doc.path = null || undefined or to use Document.toObject() method to turn mongoose doc to plain object and from there use it as usual.
Read more in mongoose api-ref:
http://mongoosejs.com/docs/api.html#document_Document-toObject
Example would look something like this:
User.findById(id, function(err, user) {
if (err) return next(err);
let userObject = user.toObject();
// userObject is plain object
});
the problem with all of these answers is that they work for one field. for example let's say i want delete all fields from my Document if they were an empty string "".
First you should check if field is empty string put it to $unset :
function unsetEmptyFields(updateData) {
const $unset = {};
Object.keys(updatedData).forEach((key) => {
if (!updatedData[key]) {
$unset[key] = 1;
delete updatedData[key];
}
});
updatedData.$unset = $unset;
if (isEmpty(updatedData.$unset)) { delete updatedData.$unset; }
return updatedData;
}
function updateUserModel(data){
const updatedData = UnsetEmptyFiled(data);
const Id = "";
User.findOneAndUpdate(
{ _id: Id },
updatedData, { new: true },
);
}
I believe that, if you desire remove a specific field into a collection, you should do this:
User.remove ({ key_to_delete: req.params.user.key_to_delete});
you can use
delete user._doc.key
I have a function that is needed to get results.
When I give 1 as _id filter everything is OK.
collectionPersonnel
.find({ '_id' : 1 })
.toArray(function (err, personnel) {
console.log(personnel);
});
If I give filter another way for instance user[0]['personnel_id'] -that is store 1- then I get only [] result;
collectionPersonnel
.find({ '_id' : user[0]['personnel_id'] })
.toArray(function (err, personnel) {
console.log(personnel);
});
And then I've tried another way. But it doesn't work because I used a string(user[0]['personnel_id']) instead of an ObjectID.
var ObjectID = require('mongodb').ObjectID;
var personnelPK_Hex = (user[0]['personnel_id']).toHexString();
var personnelPK = ObjectID.createFromHexString(personnelPK_Hex);
What should I do?
Edit
All of my codes are below;
module.exports = {
show: function(req, res) {
User.native(function(err, collectionUser) {
if(err) {
console.log("There is no exist a User by current_id");
};
collectionUser
.find({'_id' : req.param('id')})
.toArray(function (err, user) {
Personnel.native(function(err, collectionPersonnel) {
if(err) {
// handle error getting mongo collection
console.log("There is no exist a Personel by current _id");
};
if(!collectionPersonnel) {
console.log("There is no exist a Personel by current _id");
};
// var ObjectID = require('mongodb').ObjectID;
// var personnelPK_Hex = (user[0]['personnel_id']).toHexString();
// var personnelPK = ObjectID.createFromHexString(personnelPK_Hex);
collectionPersonnel
.find({ '_id' : user[0].personnel_id })
.toArray(function (err, personnel) {
console.log(personnel);
});
});
});
});
}
};
And console's output is;
[]
Solved
Just like apsillers's said. I had given a numeric _id to collection, incorrectly.
I've fixed _id value and everything is OK.
Thank you all...
user[0]['personnel_id'] might be a string. For Mongo, "1" is different from 1, which is why your literal number 1 worked, but your variable (which holds a string) does not.
Instead, try using a unary plus to convert the string to a number: +user[0]['personnel_id'].
try to use like user[0].personal_id instead of user[0]['personnel_id'] please provide your schema design that would be better to figure out what exactly you are missing.
i tried like this
collectionPersonnel
.find({ '_id' : user[0].personnel_id })
.toArray(function (err, personnel) {
console.log(personnel);
});
I'm getting a duplicate document when using the mongodb-native-driver to save an update to a document. My first call to save() correctly creates the document and adds a _id with an ObjectID value. A second call creates a new document with a text _id of the original ObjectID. For example I end up with:
> db.people.find()
{ "firstname" : "Fred", "lastname" : "Flintstone", "_id" : ObjectId("52e55737ae49620000fd894e") }
{ "firstname" : "Fred", "lastname" : "Flintstone with a change", "_id" : "52e55737ae49620000fd894e" }
My first call correctly created Fred Flinstone. A second call that added " with a change" to the lastname, created a second document.
I'm using MongoDB 2.4.8 and mongo-native-driver 1.3.23.
Here is my NodeJS/Express endpoint:
app.post("/contacts", function (req, res) {
console.log("POST /contacts, req.body: " + JSON.stringify(req.body));
db.collection("people").save(req.body, function (err, inserted) {
if (err) {
throw err;
} else {
console.dir("Successfully inserted/updated: " + JSON.stringify(inserted));
res.send(inserted);
}
});
});
Here is the runtime log messages:
POST /contacts, req.body: {"firstname":"Fred","lastname":"Flintstone"}
'Successfully inserted/updated: {"firstname":"Fred","lastname":"Flintstone","_id":"52e55737ae49620000fd894e"}'
POST /contacts, req.body: {"firstname":"Fred","lastname":"Flintstone with a change","_id":"52e55737ae49620000fd894e"}
'Successfully inserted/updated: 1'
Why doesn't my second update the existing record? Does the driver not cast the _id value to an ObjectID?
What you are posting back the 2nd time contains a field named "_id", and it's a string. That is the problem.
Look at the document, what the save method does is a "Simple full document replacement function". I don't use this function quit often so here's what I guess. The function use the _id field to find the document and then replace the full document with what you provided. However, what you provided is a string _id. Apparently it doesn't equal to the ObjectId. I think you should wrap it to an ObjectId before passing to the function.
Besides, the save method is not recommended according to the document. you should use update (maybe with upsert option) instead
I don't exactly know why a second document is created, but why don't you use the update function (maybe with the upsert operator)?
An example for the update operation:
var query = { '_id': '52e55737ae49620000fd894e' };
db.collection('people').findOne(query, function (err, doc) {
if (err) throw err;
if (!doc) {
return db.close();
}
doc['lastname'] = 'Flintstone with a change';
db.collection('people').update(query, doc, function (err, updated) {
if (err) throw err;
console.dir('Successfully updated ' + updated + ' document!');
return db.close();
});
});
And now with the upsert operator:
var query = { '_id': '52e55737ae49620000fd894e' };
var operator = { '$set': { 'lastname': 'Flintstone with a change' } };
var options = { 'upsert': true };
db.collection('people').update(query, operator, options, function (err, upserted) {
if (err) throw err;
console.dir('Successfully upserted ' + upserted + ' document!');
return db.close();
});
The difference is that the upsert operator will update the document if it exist, otherwise it will create a new one. When using the upsert operator you should keep in mind that this operation can be underspecified. That means if your query does not contain enough information to identify a single document, a new document will be inserted.
I would like to retrieve some data from a Mongoose setting in my Node.js application. I noticed that no matter what I write as field selection, I always get the _id field. Is there a way not to fetch it?
This is how I do right now:
Transaction.find({username : user.username}, ['uniqueId', 'timeout', 'confirmation_link', 'item_name'], function(err, txs){
console.log("user : " + user.username + " with txs: " + txs);
callback(txs);
});
And logs me the results which contain the _id field.
Another way is to use text argument with prefix - which will exclude this or that field from the result:
Entity.find({ ... }, '-_id field1 field2', function(err, entity) {
console.log(entity); // { field1: '...', field2: '...' }
});
_id must be specifically excluded. For example,
Transaction.find({username : user.username}, { '_id': 0, 'uniqueId' :1, 'timeout': 1, 'confirmation_link': 1, 'item_name': 1}, function(err, txs){
console.log("user : " + user.username + " with txs: " + txs);
callback(txs);
});
Another approach:
Augment the .toJSON() of the schema that it deletes the _id and the __v fields
Call .toJSON() on all DB objects sent to client
Extra benefit #1: you can use item.id === 'something' because typeof id === 'string', not ObjectId.
Extra benefit #2: When you got gan object back from the client and you want to search / update then you don't have to manually delete _id because there is none, just an id which is ignored.
Augmenting JSON:
mySchema.set('toJSON', {
virtuals: true,
transform: (doc, ret, options) => {
delete ret.__v;
ret.id = ret._id.toString();
delete ret._id;
},
});
So you can use:
let item = (await MyCollection.findOne({/* search */}).exec()).toJSON();
if (item.id === 'someString') return item;
I know it's ugly. But it's the best bad idea that I have so far.
In 5.2.13 version of Mongoose (Sept 2018)- using the query builder approach the same can be converted to
async function getUserDetails(user) {
try {
if (!user || !user.name) return;
const result = await Transaction.
find({username : user.username}).
select('uniqueId timeout confirmation_link item_name -_id');
// Adding minus sign before the _id (like -_id) in the select string unselects the _id which is sent by default.
console.log(result);
} catch(ex) {
return ex
}
}
The easiest thing you can do is something like this:
Transaction.find({username : user.username}, {_id: 0}, (err, txs) => {
// the return document won't contain _id field
// callback function body
}
Just remember that in the second object passed in the find()-
Pass 0 as the value to the specific key that you wish not to fetch
from the mongodb database.
Pass 1 as the value when you wish to
fetch from the mongodb database.