When I execute the following kind of query with MongooseJS:
Place
.find({location:{$geoWithin:{$box:[[0, -40],[151.0983703,-33.8674744]]}}})
.exec(function(err, places) {
...
});
I get zero results and the following message returned in the err
[Error: Can't use $geoWithin with Array.]
Yet if I execute the exact same criteria directly against MongoDB, on the command line:
> db.places.find({location:{$geoWithin:{$box:[[0, -40],[151.0983703,-33.8674744]]}}})
I get the correct list of records shown in the output.
What am I doing wrong with the MongooseJS code?
Looks like $geoWithin wasn't implemented in the version of Mongoose that I'm using.
My solution for the time being is to use the native mongodb library, until the stable build of Mongoose is updated with support for $geoWithin.
var mongodb = require('mongodb');
mongodb.MongoClient.connect(app.get('mongodb connection string'), function(err, db) {
if (err) throw err;
db.collection('places')
.find({location:{
$geoWithin:{
$box:[[Number(req.query.northEastLng), Number(req.query.northEastLat)],
[Number(req.query.southWestLng), Number(req.query.southWestLat)]]}}})
.toArray(function(err, results) {
if (!results)
results = [];
res.render('nearbyplaces', {
results: results
});
db.close();
});
});
This works fine.
(Note: if you really want to use Mongoose, you could download the latest unstable build from their Github page. I'd just prefer not to, because it would complicate deployment of my app. I want to be able to download everything with just npm install).
Related
My node app will crash when i send req for update the field value in my mongo db. The data will updated successfully, But The message will no show which is i provided in (
(err) => {
if (err) {
res.status(500).json({
error: "There was an error in server side!",
});
} else {
res.status(200).json({
message: "value updated successfully!",
});
}
}
)
Instead of showing above message. the mongo sent me (const err = new MongooseError('Query was already executed: ' + str);). this message and more :
MongooseError: Query was already executed: Todo.updateOne({ _id: new ObjectId("6243ed2b5e0bdc9ab780b4d9...
But I use each and every time different id and update with differen message.
when i check in db is that the old value updated or not, but nicely the old value updated. but no message or any thing i can't see in postman resposnse.Also in my console the mongodb throw me above error.
What ever happened I want to see my predefined err messages or successfully messages.
Finally, I got and understood the answer. Actually, I am a beginner programmer and developer that's why I made this problem and it took a lot of time to solve. I solved the problem within 3-5 minutes by removing async/await but I took a lot of time to dig out why it's working after removing async/await. Here is a basic concept of asynchronous programming if we use async/await we don't have to use callback again, Or if we use callback we don't need async/await Because it's just redundant. So, if we want to get data like we are getting from
callback(err,data) =>{
res.send(data);
}
then we just assigned our full thing in a variable like:
try{
const data=await (our code);
res.send(data);
}catch(err){
res.send(err.message);
}
I am trying to create a capped collection in MongoDB using NodeJS driver.
db.createCollection(req.body.name,options,function onCreateCollection(mongoErr,mongoCollection){
if(mongoErr){
...
}else{
console.log( mongoCollection.collectionName );
...
}
});
The collection name prints on the console but show collections does not list it. I tried a hyphenated name this-is-a-collection.
Why is that?
Also, what are the limitations in naming a collection?
I don't know why your code doesn't work. But I just tried to create a collection with the hyphenated name this-is-a-collection with this simple script, it worked.
var MongoClient = require('mongodb').MongoClient;
var url = 'mongodb://localhost:27017/db';
MongoClient.connect(url, function(err, db) {
console.log("Connected correctly to server");
db.createCollection('this-is-a-collection', { capped : true, size : 10000 } ,function onCreateCollection(err,mongoCollection){
if(err){
console.log(err);
} else {
console.log(mongoCollection.collectionName);
}
db.close();
});
});
And in the CLI :
MBP:mongo sapher$ mongo
MongoDB shell version: 3.0.5
connecting to: test
....
> use db
switched to db db
> show collections
system.indexes
this-is-a-collection
You can follow this link to get more info on MongoDB naming restrictions.
For naming convention, I personnaly use snake case like remote_users. I think this is the most elegant way to name a collection. Naming isn't that important as long as you stay consistent.
As it turns out, on older version of the driver 1.4.x, creating a capped collection without specifying the size option doesn't result in an error. It even returns a success response. On the newer version, 2.0.x, it does result in an error.
For a capped collection, size is needed while max is optional. The docs are slightly ambiguous as they do not state that you need a size to create a capped collection.
I have a weird issue where I have a test to see prove that you cannot create a new user if a user with the same name/email exists, however it always seems to fail. However when I look at the first step which adds a user to the database with the details expected, it inserts and calls back with the document:
[ { Username: 'AccountUser',
Email: 'some#email.com',
CreatedDate: Mon Sep 22 2014 12:52:48 GMT+0100 (GMT Summer Time),
_id: 54200d90d0a34ffc1565df13 } ]
So if I do a console.log of the documents returned from insert thats what I get which is ok, and the _id has been set by mongo which is correct, so I know the call succeeded, and there was no errors.
However if I then go and view the database (MongoVUE) that collection is empty, so I am a bit baffled as to why this is happening.
I am using pooled mongodb connections (i.e setting up during app setup then using app.set("database_connection", database);. So I am a bit baffled as to why this is happening?
Here is some example code, which is part of larger code but basically is contained within promises:
// Point of connection creation
var mongoClient = mongodb.MongoClient;
var connectionCallback = function (err, database) {
if (err) { reject(err); }
resolve(database);
};
try
{ mongoClient.connect(connectionString, connectionCallback); }
catch(exception)
{ reject(exception); }
// Point of usage
var usersCollection = connection.collection("users");
usersCollection.insert(userDocument, function(err, docs) {
if(err) {
reject(err);
return;
}
console.log(docs);
resolve(docs[0]);
});
So I create the connection and pass back the database for use elsewhere, then at the point of inserting I get the connection, get the collection and then insert into it, and log the documents added, which is what is in the above log output.
Also finally running:
Windows 8.1
Node 0.11.13
npm mongodb latest
MongoDB 2.6.1
Not the answer I was hoping for, but I restarted the computer (rare occurrence) and the issue no longer occurs. I have no idea what was causing it and I am still slightly worried incase it happens again, but for now I am up and running again.
I was going through the mongodb and nodejs course on MongoDBUniversity and one of the task involves finding the documents which has the highest recorded temperature for any state and then add a field "month_high" to it.I am able to find the documents for the state with the highest temperature but am unable to update it. The code is as below.
Can someone tell me what might I be doing wrong?
var MongoClient=require('mongodb').MongoClient;
MongoClient.connect('mongodb://localhost:27017/course',function(err,db){
var cursor=db.collection("weather").find();
cursor.sort({"State":1,"Temperature":-1});
var oldState,newState;
cursor.each(function(err,doc){
if(err)throw err;
if(doc==null){
return db.close();
}
newState=doc.State;
if(newState!=oldState){
var operator={'$set':{"month_high":true}};
var query={"_id":doc._id};
console.log(doc._id+" has temp "+doc.Temperature+" "+doc.State);
db.collection("weather").update(doc,operator,function(err,updated){
console.log("hi");//---->Never Logs
if(err)throw err;
// console.log(JSON.stringify(updated));
})
}
oldState=newState;
});
});
I'm not 100% sure, but given the syntax reported on the docs you might have to specify the options parameter even if not using it:
db.collection("weather").update(doc,operator, options, function(err,updated)
Also, the connection might get closed before the callbacks are called. Does it change anything if you remove the db.close() call?
Collection name is 'data'. In this homework 'weather' is database name.
See
https://education.mongodb.com/courses/10gen/M101JS/2013_October/courseware/CRUD/Homework_2.2/
> use weather
switched to db weather
> db.data.findOne()
In the following code:
var MongoClient = require('mongodb').MongoClient;
MongoClient.connect('mongodb://localhost:27017/db_name', function(err, db){
if (err) throw err;
var collection = db.collection('col_name');
console.log(collection.find().toArray(function(err, items){}));
});
When I run the above, it doesn't return any results and instead returns undefined. What am I missing?
Also, in order to confirm there exist some collections on the db, which there are, I tried to add console.log(db.getCollectionNames());, but it looks like it has no such method in Node.js driver. So is it still possible to confirm the existence of collections? (Anyway I just want to use it as debug in these situations - usually I don't need the method though).
Thanks.
Don't log your entire find() function, do the checking in the callback:
collection.find().toArray(function(err, items){
console.log(items);
});
For the getCollectionNames() part, the method is actually called collectionNames() in the mongodb native driver :
db.collectionNames(function (err, list) {console.log(list)});