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Unable to access writeresult from remove() in callback

I'm pretty new to Mongodb and have so far successfully used Find, Insert, Update methods. However, with Delete function I am not able to access WriteResult
Insert (Works)
productCollection.insert(newProduct, function (err, result) {
callBack(err, { message: result["insertedCount"] + ' product created successfully.' });
});
Find (Works)
productCollection.find({}).toArray(function (err, docs) {
callBack(err, { product: docs });
});
Delete (Has Issues)
productCollection.remove({ id: pId }, { justOne: 1 }, function (err, result) {
callBack(err, { message: result});
});
Here when I return {message: result} I get
{
"message": {
"ok": 1,
"n": 0
}
}
But I want to actually read "n" from Result to show no of documents deleted
Tried following
{ message: result["n"] }
{ message: result["nRemoved"] }
But in both cases it returns empty object {}.

According to the 2.0 version of Node.js MongoDB Driver API, remove() method is deprecated, you can use removeOne() method instead:
http://mongodb.github.io/node-mongodb-native/2.0/api/Collection.html#remove
In order to receive number of documents that were removed, you need to use safe mode to ensure removal of documents. To do this, specify write concern by passing {w: 1} to removeOne() function:
productCollection.removeOne({ _id: pId }, { w:1 }, function(err, r) {
// number of records removed: r.result.n
callBack(err, { message: r });
});
Hope this helps.

Thanks Yelizaveta for pointing out the deprecated method. However in my case, following worked
productCollection.removeOne({ id: pId }, { w: 1 }, function (err, r) {
callBack(err, { message: r.result["n"]});
});
I could not get r.result.n working instead r.result["n"] worked, which I don't understand.

Get all collection records related to a model

// Note model
attributes: {
// Relations
notebook: {
model: 'Notebook'
},
}
and
// Notebook
attributes: {
// Relations
owner: {
model: 'User'
},
notes: {
collection: 'Note',
via: 'notebook'
}
}
in the controller:
Notebook.findOne({owner: user.id}, function (err, notebook) {
if (err || !notebook) {
return res.serverError(err);
}
// --> until here it goes all fine, finding the Notebook
Note.find().where({notebook: notebook.id}, function (err, notes) {
if (err || !notes) {
return res.serverError(err);
}
return res.json({notebook: notebook, notes: notes});
})
})
It is clear that I am trying to get all Notes related to the Notebook. When debugging, I get until the Note.find() and then I don't even enter the callback, so I don't get any results for Note. The err is null, so I wouldn't know if something's wrong.
I am betting that I have set up my model relations wrongly, but it seems correct to me, as from what I have read in tutorials.
P.S. I do have the records in the database, and the ER relations there are setup correctly, because inserting Note records works without problems.

The models relations seems to be fine.
I think the error come from the fact that there is no callback param in the where method.
Try this instead:
Note
.find()
.where({ notebook: notebook.id })
.exec(function (err, notes) {
...
});

Is it possible to update an already open document in mongodb

In JS, Is there a better way of doing the following:
I'm finding a user, and then checking password, then I wish to update the same users' document.
Can I leverage the already open document (var doc) for updating? Or do as the code below does and re-search for name:name when updating.
user_collection.findOne({ name:name }, function(err, doc) {
if(err)
throw err;
if(doc) {
// verify doc.password etc
user_collection.update({ name:name }, {$set: { last_joined:last_joined }}, { upsert:true }, function(err, doc) {
if(err) {
// log error
}
});
}
});

Yes - use the save method.
The document you have in doc is an in-memory copy of the record in the database. If you want to modify it then save it to the database, you need to either use the update method as you do, or use save(modified_doc).
Note: as freakish said, you probably should use user_collection.update({ _id: doc._id }, ...) instead of searching for name again, since it may not be unique.

Allow collection to update from client in Meteor

Just hit an insanely frustrating roadblock in prototyping. I need to update and increment values an array inside of a collection. To do this, I'm accessing the collection using the MongoDB syntax like so:
Players.update({_id: Session.get('p1_id'), 'opponents.$.id' : Session.get('p2_id')},
{$inc: {
'games_played' : 1
}}
);
When this runs I get an error saying: Uncaught Error: Not permitted. Untrusted code may only update documents by ID. [403]
Now, I searched the hell out of this and I know that it came down in an update and why they only allow update by id's. But my problem is that I can't seem to find a way around it. I tried forcing it by adding this to if (Meteor.isServer):
Players.allow({
insert: function(userId, doc, fields, modifier){
return true;
},
update: function(userId, doc, fields, modifier){
return true;
},
remove: function(userId, doc, fields, modifier){
return true;
}
});
Nothing seems to work, and all the examples I find talk about using a Meteor method (not really sure what that is) or are doing userId validation (I dont have any users and don't want to add them right now). I'm just prototyping/sketching and I'm not concerned about security. How can I proceed here?

Here's how you can make this into a method:
Meteor.methods({
incrementGames: function (player1Id, player2Id) {
check(player1Id, Meteor.Collection.ObjectID);
check(player2Id, Meteor.Collection.ObjectID);
Players.update({
_id: player1Id,
'opponents.$.id': player2Id
}, {
$inc: {
'games_played' : 1
}
}, function(error, affectedDocs) {
if (error) {
throw new Meteor.Error(500, error.message);
} else {
return "Update Successful";
}
});
}
});
And on your client:
Meteor.call("incrementGames", Session.get('p1_id'), Session.get('p2_id'), function(error, affectedDocs) {
if (error) {
console.log(error.message);
} else {
// Do whatever
}
});

You just got the update wrong. The first parameter of the update method should be the id. the second parameter is an object containing the modifiers.
Players.update(playerId, {$inc:{games_played:1}});
Optionally you can add a callback containing error as the first parameter and response as the second parameter.

node + mongo: updating a record requires a callback

So I'm listening for an event with socket.io, once that fires I'm trying to update a record to a new value.
socket.on('contentEdited', function (newContent) {
collection.update(
{ '_id' : ObjectId("5279262e74d92da751eb2b8e") },
{ $set: {
'content': newContent
}
}
), function (err, result) {
if (err) throw err;
console.log(result)
};
});
The syntax works in the shell, but throws the following error in node when the event fires:
Error: Cannot use a writeConcern without a provided callback
I tried adding an function at the end afterwards for basic error checking, but I'm not sure how to provide a callback in the way mongo expects.
Still kinda new to this, thanks

I think your problem is that the callback function needs to be inside the update function call instead of outside it. The format for the nodejs MongoDB driver can be found here: http://mongodb.github.io/node-mongodb-native/api-generated/collection.html#update
So it should look like this:
collection.update(
{ '_id' : ObjectId("5279262e74d92da751eb2b8e") },
{ $set: { 'content': newContent } },
function (err, result) {
if (err) throw err;
console.log(result);
})
Note that the parentheses has moved after the callback function.
You could also set the write concern to "unacknowledged" instead of "acknowledged."
The MongoDB concept of "Write Concerns" determines how certain you want to be that MongoDB successfully wrote to the DB. The lowest level of write concern, "Unacknowledged" just writes data to the server and doesn't wait to response. This used to be the default, but now the default is to wait for MongoDB to acknowledge the write.
You can learn more about write concerns here:
http://docs.mongodb.org/manual/core/write-concern/
To set the write concern to unacknowledged, add the option {w: 0}:
collection.update(
{ '_id' : ObjectId("5279262e74d92da751eb2b8e") },
{ $set: { 'content': newContent } },
{ w : 0 });

yes. maybe you have the wrong syntax. and this might make it even better
socket.on('contentEdited', function (newContent) {
collection.update(
{ '_id' : ObjectId("5279262e74d92da751eb2b8e") },
{ $set:
{ 'content': newContent }
},
{returnOriginal : false},
function (err, result) {
if (err) throw err;
console.log(result);
});
})