Hey guys not giving an example since the question is pretty straightforward.
I have a mongodb schema in which I have a field called Teamnames which is an array so
Teamnames: [String]
I am using body parser middleware to accept data from a form on my client side. There are about 10 different text boxes each having name as teamname1, teamname2, etc etc .
Whats the right syntax to update the mongodb field? I am doing findOneAndUpdate to retrieve the record from my collection after submitting the update and I wanted to update the Teamname array with the values. But I am kind of confused with the syntax and whats the right way to approach this. Can someone please help?
Try this:
const value = await YourModel.findByIdAndUpdate(id, {
$set: { teamnames: yourFormData }
},
{
new: true,
upsert: true,
});
Related
I'm using MongoDB and Mongoose with Express to store tweets that I retrieve via the Twitter API.
I want to avoid saving duplicate tweets. I am doing something like that :
TweetsModel.find({tweet_id: tweet.tweet_id}, function (err, tweets) {
if(tweets.length > 0){
cb('Tweet already exists',null);
} else{
tweet.save(function(err){
cb(err,user);
});
}
});
My question is : for performance reason, is there a way using Mongoose to avoid doing two requests ? One find and one save ?
Knowing that I don't want to update the tweet if it already exists either.
Thank you
You can use an update call with the upsert option to do this:
TweetsModel.update(
{tweet_id: tweet.tweet_id},
{$setOnInsert: tweet},
{upsert: true},
function(err, numAffected) { .. }
);
If a doc already exists with that tweet id, then this is a no-op. Otherwise it will add the doc.
$setOnInsert requires v2.4+ of MongoDB. If your version is less than 2.4, things get more complicated.
Hi im trying to simply remove a document from a collection using mongoose but for some strange reason I cannot get it to work.
Here is the code:
function deleteUserevent()
{console.log('in delete User Event');
models.Userevent.remove({ _id: "5214f4050acb53fe31000004"}, function(err) {
if (!err){
console.log('deleted user event!');
}
else {
console.log('error');
}
});
}
Can anyone help me out on my syntax? I know the _id is stored as new ObjectId("5214f4050acb53fe31000004") but I have tried this with no joy?
Thanks.
In MongoDB, the "_id" field of documents is of type ObjectId, as you mentioned. This is not equal to a String, so running the query
db.userevent.remove({ _id: "5214f4050acb53fe31000004"});
will not match anything, and will not remove anything. Instead, you must search for a document where the _id field is an ObjectId with that value:
db.userevents.remove({ _id: ObjectId("5214f4050acb53fe31000004")});
In mongoose, you can use the findByIdAndRemove command to remove a document with a specific _id. This command takes either an ObjectId or a String as an argument, so
query = Userevent.findByIdAndRemove("5214f4050acb53fe31000004");
should work just fine.
Just add exec() after query.
It should work like this:
await models.Userevent.findByIdAndDelete("5214f4050acb53fe31000004").exec()
I've just started to look at meteor and I'm stuck trying to update a record within an array within a record. Say i have a document that looks something like this:
Users:
{
_id: "somerandom",
name: "name1",
items, [
{
name: "item1",
data: "somedata",
...
},
{
name: "item2",
data: "somedata",
...
}
],
...
},
...
And I want to update the data of items 'item1'. I can't find anything on how to do this in meteor, but from what I have read about MongoDB I think that the correct way would be something like
Users.update({_id: userId, "items.name": 'item1}, {$set: {"items.$.data": newData}});
but since the MongoDB used in Meteor doesn't support $ it won't work, on the other hand I might be way of how this should be done.
Does anyone have a solution for this?
Use Meteor.methods() and implement your database operation on the server side and call it using Meteor.call() from the client. This feature is not yet implemented in Meteor and it is documented here.
You can read more in the discussion on this issue raised on Github, here.
I found a workaround at meteor's github https://github.com/meteor/meteor/blob/master/examples/parties/model.js
The idea is to first get the index of the array-item you want to change and then use that index instead of $. So in this case it would be something like
user = Users.findOne(userId);
index = _.indexOf(_.pluck(user.items, 'name'), 'item1');
modifier = {$set: {}};
modifier.$set["items." + index + ".data"] = newData;
Users.update(userId, modifier);
I'm wondering the best way to query mongo db for many objects, where each one has an array of _id's that are attached to it. I want to grab the referenced objects as well. The objects' schemas looks like this:
var headlineSchema = new Schema({
title : String,
source : String,
edits : Array // list of edits, stored as an array of _id's
...
});
...and the one that's referenced, if needed:
var messageSchema = new Schema({
message : String,
user : String,
headlineID : ObjectId // also contains a ref. back to headline it's incl. in
...
});
One part of the problem (well, depending if I want to keep going this route) is that pushing the message id's is not working (edits remains an empty array [] afterwards) :
db.headline.update({_id : headlineid}, {$push: {edits : messageid} }, true);
When I do my query, I need to grab about 30 'headlines' at a time, and each one could contain references to up to 20 or 30 'messages'. My question is, what is the best way to fetch all of these things? I know mongo isn't a relational db, so what I'm intending is to first grab the headlines that I need, and then loop through all 30 of them to grab any attached messages.
db.headline.find({'date': {$gte: start, $lt: end} }, function (err, docs) {
if(err) { console.log(err.message); }
if(docs) {
docs.forEach(function(doc){
doc.edits.forEach(function(ed){
db.messages.find({_id:ed}, function (err, msg) {
// save stuff
});
});
});
}
});
This just seems wrong, but I'm unsure how else to proceed. Should I even bother with keeping an array of attached messages? I'm not married to the way I've set up my schema, either. If there is a better way to track relationships between them, or a better query to achieve this, please let me know.
Thanks
Does each message belong to only one headline? If so, you can store the headline id as part of each message. Then for each headline, do:
db.messages.find({headline_id: current-headline-id-here})
You could try using the $in operator for selecting a list of ObjectIds
http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-%24in
For this app, I'm using Node.js, MongoDB, Mongoose & Express
So I have a Param Object that contains an array of Pivots, and I want to read certain data from the pivots as outlined below
---in models.js-------------------------
var Pivot = new Schema({
value : String
, destination : String
, counter : Number
});
var Param = new Schema({
title : String
, desc : String
, pivots : [Pivot]
});
------------- in main.js --------------
var Param = db.model('Param');
app.get('/:title/:value', function(req, res){
Param.findOne({"title":req.param('title')}, function(err, record){
console.log(record.pivots);
record.pivots.find({"value":req.param('value')}, function(err, m_pivot){
pivot.counter++;
res.redirect(m_pivot.destination);
});
record.save();
});
});
I know that the code works until console.log(record.pivots), since i got a doc collection with the right pivot documents inside.
However, there does not seem to be a find method to let me match an embedded document by the 'value' property defined in the schema. Is it possible to search through this array of embedded documents using .find() or .findOne() , and if not, is there some easy way to access it through mongoose?
varunsrin,
This should do it
app.get('/:title/:value', function(req, res) {
Param.findOne({'pivots.value': req.param('value'), "title":req.param('title')}},
function(err, record) {
record.pivot.counter++;
res.redirect(m_pivot.destination);
record.save();
});
});
Note the pluralization of the query to match the field name in your schema
You can querying using embedded document properties like this:
{'pivot.value': req.param('value')}}
Update in response to comment:
app.get('/:title/:value', function(req, res) {
Param.findOne({'pivot.value': req.param('value'), "title":req.param('title')}},
function(err, record) {
record.pivot.counter++;
res.redirect(m_pivot.destination);
record.save();
});
});
I solved it temporarily using a simple for loop to parse the object array as follows:
for (var i=0; i <record.pivots.length; i++){
if (record.pivots[i].value == req.param('value')){
res.redirect(record.pivots.destination);
}
}
However, I still think that Mongoose must have a simpler way of interacting with embedded documents - and this loop is somewhat slow, especially when the number of embedded documents grows large.
If anyone has any suggestions for a faster way to search this object array either in js or with a mongoose function, please post below.
the biggest problem with this is that if your req has some fields empty (that should act as wildcard), you will not find anything since mongo tries to match empty params as well, so searching for {"user":"bob", "color":""} is not the same as {"user":"bob", "color":"red"} or {"user":"bob"}. this means that you have to first create a query object and filter out any unused parameters before you pass it in, and if you create a query object, you can no longer do something like "user.name=..." because mongo interperets this as an error since it does not first resolve the object literal into a string.
Any ideas on this problem?
ps. You'd think it would be easy enough to make an object like:
user.name="bob"; user.color:"green"; user.signup.time="12342561"
and then just use user as a query object :/
I think you are looking for the "$in" keyword?
As in:
{a: {$in: [10, "hello"]}}
source: MongoDB Queries CheatSheet