I use this code to store my data into MongoDB database but it does not view in the database .. and when I use find() to find, it shows my data but not shows when I use db.pick.find() in command. I may be missing something when I setup mongo so please help me.
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/pick', { useNewUrlParser: true })
mongoose.connection.once('connected', function(){
console.log("Open Connection")
})
var catSchema = new mongoose.Schema({
name: String,
age: Number
});
var Cat = mongoose.model("Cat", catSchema);
var newc = new Cat({
name: "cutie",
age: "4"
});
newc.save((err,c) =>{
if(err){
console.log("NewC Err")
}else{
console.log(c)
}
});
Okay atul,
Your database's name is Pick, but when you do this query:
db.pick.findOne({}), you're technically saying that the database must find a document from the pick collection. But looking at the code, cat is the name of your collection.
you can use the show collections; command to get the collection names in mongodb and then you can query like this:
Select the Database
use pick;
get the collection list
show collections;
query the collection
db.collectionName.findOne({})
I just started learning MongoDB and mongoose. Currently I have the following structure:
database -> skeletonDatabase
collection -> adminLogin
When I run db.adminLogin.find() from the command line I get:
{ "_id" : ObjectId("52lhafkjasfadsfea"), "username" : "xxxx", "password" : "xxxx" }
My connection (this works, just adding it FYI)
module.exports = function(mongoose)
{
mongoose.connect('mongodb://localhost/skeletonDatabase');
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function callback () {
console.log('Conntected To Mongo Database');
});
}
My -js-
module.exports = function(mongoose)
{
var Schema = mongoose.Schema;
// login schema
var adminLogin = new Schema({
username: String,
password: String
});
var adminLoginModel = mongoose.model('adminLogin', adminLogin);
var adminLogin = mongoose.model("adminLogin");
adminLogin.find({}, function(err, data){
console.log(">>>> " + data );
});
}
My console.log() returns as >>>>
So what am I doing wrong here? Why do I not get any data in my console log? Thanks in advance for any help.
mongoose by default takes singular model names and pairs them with a collection named with the plural of that, so mongoose is looking in the db for a collection called "adminLogins" which doesn't exist. You can specify your collection name as the 2nd argument when defining your schema:
var adminLogin = new Schema({
username: String,
password: String
}, {collection: 'adminLogin'});
Had a problem with injecting it within an express route for my api so I changed it thanks to #elkhrz by first defining the schema and then compiling that one model I want to then pull like so:
app.get('/lists/stored-api', (req, res) => {
Apis.find(function(err, apis) {
if (err) return console.error(err);
res.send(apis);
});
});
I wouldn't send it to the body, I would actually do something else with it especially if you plan on making your API a production based application.
Run through this problem and read up on possible proper ways of rendering your data:
How to Pass Data Between Routes in Express
Always a good idea to practice safe procedures when handling data.
first compile just one model with the schema as an argument
var adminLogin = mongoose.model('adminLogin', adminLogin);
in your code adminLogin does not exist, adminLoginModel does;
after that ,instead to
adminLogin.find({}, function(err, data){
console.log(">>>> " + data );
});
try this
adminLogin.find(function (err, adminLogins) {
if (err) return console.error(err);
console.log(adminLogins);
is important the "s" because mongo use the plural of the model to name the collection, sorry for my english...
In meteor, if you start meteor mongo, you get a shell, where you can access the database purely as mongo.
project :: (master*) ยป meteor mongo
MongoDB shell version: 2.6.7
connecting to: 127.0.0.1:3001/meteor
Mongo-Hacker 0.0.4
meteor:PRIMARY> db.users.find().count()
6
meteor:PRIMARY>
I want to access the item that is like the db, but with Meteor. For a simple example,
function getTableEntityCount(tablename) {
return db[tablename].find().count();
}
Is this possible in Meteor?
You can try with the mongodb native driver.
// Server code
//Typical require
var mongodb = Meteor.npmRequire("mongodb"), //using arounfa meteorhacks:npm
db = mongodb.Db,
mongoclient = mongodb.MongoClient,
Server = mongodb.Server,
db_connection = new Db('cats', new Server("127.0.0.1", 27017 {auto_reconnect: false}));
db.open(function(err, db) {
db.authenticate('<username>', '<password>', function(err, result) {
//return db[tablename].find().count();
});
});
This is just conceptual code.
I think now you can use this method:
MyCollection.rawCollection()
https://docs.meteor.com/api/collections.html#Mongo-Collection-rawCollection
I am new to mongodb and node.js. I have a simple node.js app that in order to run I have to run the command
mongod
to make sure mongodb is running.
locally this works fine.
now I am moving to heroku, I createrd a Procfile where I declare :
web: node http.js
so this take care of starting node.js.
Now how can I call the command
mongod
on heroku?
Update
before the heroku requirement this is how I used to initialize my mongodb :
var mongo = require('mongodb');
var Server = mongo.Server,
Db = mongo.Db,
BSON = mongo.BSONPure,
ObjectID = mongo.ObjectID;
var server = new Server('localhost', 27017, {auto_reconnect: true});
db = new Db('sampledb', server);
db.open(function(err, db) {
if(!err) {
console.log("Connected to 'sampledb' database");
db.collection('sample', {strict:true}, function(err, collection) {
if (err) {
console.log("The 'sample' collection doesn't exist. Creating it with sample data...");
populateDB();
}
});
}
});
in order to accomodate heroku here is how I initialize mongodb :
var mongo = require('mongodb');
var Server = mongo.Server,
Db = mongo.Db,
BSON = mongo.BSONPure,
ObjectID = mongo.ObjectID;
var mongoUri = process.env.MONGOLAB_URI ||
process.env.MONGOHQ_URL ||
'mongodb://localhost/sampledb';
mongo.Db.connect(mongoUri, function (err, db) {
db.collection('sample', function(er, collection) {
if (err) {
console.log("The 'sample' collection doesn't exist. Creating it with
sample data...");
populateDB();
}
});
});
Now this throws an error because db is not recognized. I think I am missing a conceptual issue here, I am new to this world all together.
any help is appreciated.
You don't call the command mongod on heroku.
You'd add one of the mongo add-ons from addons.heroku.com to your app, then have your code connect to the credentials in the config variable exported to your app by the add-on provider.
I have a large collection of 300 question objects in a database test. I can interact with this collection easily through MongoDB's interactive shell; however, when I try to get the collection through Mongoose in an express.js application I get an empty array.
My question is, how can I access this already existing dataset instead of recreating it in express? Here's some code:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/test');
mongoose.model('question', new Schema({ url: String, text: String, id: Number }));
var questions = mongoose.model('question');
questions.find({}, function(err, data) { console.log(err, data, data.length); });
This outputs:
null [] 0
Mongoose added the ability to specify the collection name under the schema, or as the third argument when declaring the model. Otherwise it will use the pluralized version given by the name you map to the model.
Try something like the following, either schema-mapped:
new Schema({ url: String, text: String, id: Number},
{ collection : 'question' }); // collection name
or model mapped:
mongoose.model('Question',
new Schema({ url: String, text: String, id: Number}),
'question'); // collection name
Here's an abstraction of Will Nathan's answer if anyone just wants an easy copy-paste add-in function:
function find (name, query, cb) {
mongoose.connection.db.collection(name, function (err, collection) {
collection.find(query).toArray(cb);
});
}
simply do find(collection_name, query, callback); to be given the result.
for example, if I have a document { a : 1 } in a collection 'foo' and I want to list its properties, I do this:
find('foo', {a : 1}, function (err, docs) {
console.dir(docs);
});
//output: [ { _id: 4e22118fb83406f66a159da5, a: 1 } ]
You can do something like this, than you you'll access the native mongodb functions inside mongoose:
var mongoose = require("mongoose");
mongoose.connect('mongodb://localhost/local');
var connection = mongoose.connection;
connection.on('error', console.error.bind(console, 'connection error:'));
connection.once('open', function () {
connection.db.collection("YourCollectionName", function(err, collection){
collection.find({}).toArray(function(err, data){
console.log(data); // it will print your collection data
})
});
});
Update 2022
If you get an MongoInvalidArgumentError: The callback form of this helper has been removed. error message, here's the new syntax using async/await:
const mongoose = require("mongoose");
mongoose.connect('mongodb://localhost/productsDB');
const connection = mongoose.connection;
connection.on('error', console.error.bind(console, 'connection error:'));
connection.once('open', async function () {
const collection = connection.db.collection("Products");
collection.find({}).toArray(function(err, data){
console.log(data); // it will print your collection data
});
});
I had the same problem and was able to run a schema-less query using an existing Mongoose connection with the code below. I've added a simple constraint 'a=b' to show where you would add such a constraint:
var action = function (err, collection) {
// Locate all the entries using find
collection.find({'a':'b'}).toArray(function(err, results) {
/* whatever you want to do with the results in node such as the following
res.render('home', {
'title': 'MyTitle',
'data': results
});
*/
});
};
mongoose.connection.db.collection('question', action);
Are you sure you've connected to the db? (I ask because I don't see a port specified)
try:
mongoose.connection.on("open", function(){
console.log("mongodb is connected!!");
});
Also, you can do a "show collections" in mongo shell to see the collections within your db - maybe try adding a record via mongoose and see where it ends up?
From the look of your connection string, you should see the record in the "test" db.
Hope it helps!
Something else that was not obvious, to me at least, was that the when using Mongoose's third parameter to avoid replacing the actual collection with a new one with the same name, the new Schema(...) is actually only a placeholder, and doesn't interfere with the exisitng schema so
var User = mongoose.model('User', new Schema({ url: String, text: String, id: Number}, { collection : 'users' })); // collection name;
User.find({}, function(err, data) { console.log(err, data, data.length);});
works fine and returns all fields - even if the actual (remote) Schema contains none of these fields. Mongoose will still want it as new Schema(...), and a variable almost certainly won't hack it.
Go to MongoDB website, Login > Connect > Connect Application > Copy > Paste in 'database_url' > Collections > Copy/Paste in 'collection' .
var mongoose = require("mongoose");
mongoose.connect(' database_url ');
var conn = mongoose.connection;
conn.on('error', console.error.bind(console, 'connection error:'));
conn.once('open', function () {
conn.db.collection(" collection ", function(err, collection){
collection.find({}).toArray(function(err, data){
console.log(data); // data printed in console
})
});
});
I tried all the answers but nothing worked out, finally got the answer hoe to do it.
var mongoose = require('mongoose');
mongoose.connect('mongodb://0.0.0.0:27017/local');
// let model = require('./test1');
setTimeout(async () => {
let coll = mongoose.connection.db.collection(<Your collection name in plural form>);
// let data = await coll.find({}, {limit:2}).toArray();
// let data = await coll.find({name:"Vishal"}, {limit:2}).toArray();
// let data = await coll.find({name:"Vishal"}, {projection:{player:1, _id:0}}).toArray();
let data = await coll.find({}, {limit:3, sort:{name:-1}}).toArray();
console.log(data);
}, 2000);
I have also mentioned some of the criteria to filter out. Delete and update can also be done by this.
Thanks.
Make sure you're connecting to the right database as well as the right collection within the database.
You can include the name of the database in the connection string.
notice databasename in the following connection string:
var mongoose = require('mongoose');
const connectionString = 'mongodb+srv://username:password#hosturl.net/databasename';
mongoose.connect(connectionString);