I am a beginner in nodejs and mongoose. I am trying to retrieve the category value which astname having laptop. Please suggest me how to achieve this.
var astname = "Laptop";
Asset.find({ astname : astname}, function(err, foundcategory){
if(err){
console.log(err);
} else {
console.log(foundcategory.category);
}
})
foundcategory is an array in your example. Use findOne instead of find to query for a single document.
var astname = "Laptop";
Asset.findOne({ astname : astname}, function(err, foundcategory){
if(err){
console.log(err);
} else {
console.log(foundcategory.category);
}
})
Related
I get that this can be a duplicated question. I looked up at least 10 related questions and answers, but I am still not able to find the document.
I am trying to get the document using .findOne(). I have the _id that created by MongoDB. But, I get null for every search I try.
await mongoose.connection.db
.collection('testing')
.findOne({ _id: req.body.test_id }, (err, result) => {
if (err) {
res.status(400);
} else {
console.log(`whaaaaaahsidufh ${result}`);
}
});
I tried _id: mongoose.Type.ObjectId(req.body.test_id) and other possible way to search. How can I retrieve the result by using _id on mongoose?
you can use findById();
try {
const test = await mongoose.connection.db.collection('testing').findById(req.body.test_id);
if (test ) {
console.log(`whaaaaaahsidufh ${test}`);
} else {
console.log(`test not found`);
}
}catch(err){
res.status(400);
}
I wanted to delete a document with concerned _id and email when I click on "Remove task" in the HTML file.
Following is the code which removes that task:
I've passed value of email and _id(only hexadcemial string value) to the code:
collection.findOneAndDelete({email:email,_id:taskid},function (err, result) {
if (err) {
console.log(err);
} else {
console.log("Removed!");
console.log(result);
callback(result);
}
db.close();
});
But, the function is not recognizing _id that I've passed. The value of "taskid" variable is 566836bd8db43d3d56e23a4a i.e. only strings value from _id:
ObjectId("566836bd8db43d3d56e23a4a")
var taskid=566836bd8db43d3d56e23a4a;
I've tried every possible declaration of taskid to convert it so that the function could recognize the value of _id and match it:
var taskid= "ObjectId("+'"'+req.param('taskid')+'"'+")";
But till now, I am not able to match the _id with the taskid. Any fix?
if you are going to compare with ObjectId then
var ObjectId = require('mongoose').Types.ObjectId
collection.findOneAndDelete({email:email,_id:new ObjectId(taskid)},function (err, result) {
if (err) {
console.log(err);
} else {
console.log("Removed!");
console.log(result);
callback(result);
}
db.close();
});
Should work for you.
If you feel the job too hard for each and every query then you can create an new method.
String.prototype.toObjectId = function() {
var ObjectId = (require('mongoose').Types.ObjectId);
return new ObjectId(this.toString());
};
// Every String can be casted in ObjectId now
console.log('545f489dea12346454ae793b'.toObjectId());
I want to update my Document but it's not working 100% .
// Initialize connection once
MongoClient.connect("mongodb://localhost:27017/testDB", function(err, database) { //"mongodb://localhost:27017/test"
if(err) throw err;
db = database;
});
My collection row looks like:
{ "_id" : ObjectId("53f9379ce9575bbe9ec29581"), "name:paco",
"status:student" }
Now if I want to update the row over the Document as follows:
db.collection('user', function(err, collection){
collection.update({'_id':ObjectID(req.session.loggedIn)}, {image : filename}, {w:1}, function(err, result){
console.log(result);
I am getting just:
{ "_id" : ObjectId("53f9379ce9575bbe9ec29581"), "image:filename" }
How can I make an update to get my data like this??:
{ "_id" : ObjectId("53f9379ce9575bbe9ec29581"), "name:paco",
"status:student" , "image:filename"}
Doing an update the way you did it is going to retrieve the document in your collection with the specified _id, then it is going to replace the content of this document with what you specified as your second parameter. In your case, it will retrieve the document with _id 53f9379ce9575bbe9ec29581, and replace the existing fields with the field you passed, image:filename (that means the existing fields will be removed, as you noticed).
What you want to do is use the $set operator. This operator will not touch the document retrieved, but only modify the field that you specified, or add it if it does not exist.
So your update command should look something like this:
db.collection('user').update({'_id':ObjectID(req.session.loggedIn)}, {$set: {image : filename}}, {w:1}, function(err, result){
console.log(result);
to update record by _id
var ObjectID = require('mongodb').ObjectID;
exports.updateUser = function(req, res) {
var collection = db.collection('users');
collection.update(where, $set:req.body, function(err, result) {
if (err) {
console.log('Error updating user: ' + err);
res.send({'error':'An error has occurred'});
} else {
console.log('' + result + ' document(s) updated');
res.send(user);
}
});
}
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 really really need help in this. I am using node.js with mongodb and mongoose. So far I've managed to create a schema and save those into my database.
var Bericht = new Schema({
name : String
, mail : String
, betreff : String
, inhalt : String
, datum : Date
});
var Bericht = mongoose.model('Bericht', Bericht);
I habe a html formular where I can transmit with misc. fields data, by querystring I converting those into readable strings
var bericht_data = {
name: tempo.Name
, mail: tempo.Mail
, betreff: tempo.Betreff
, inhalt: tempo.Inhalt
};
var testoro = new Bericht(bericht_data);
testoro.save(function (err) {
if (!err) console.log('Success!');
});
so tempo.Name for example is a string and it also successful in saving it.
So far I can save all data from this formular into my mongodb.
Now the very problem: I want the data back as string to handle for dynamic html.
To get the info into my console, I use
Bericht.find(
{},
{ '_id': 0},
function(err, docs) {
if (!err){
console.log(docs);
// process.exit();
}
else { throw err;}
}
);
The console gives me all data which was ever saved in my schema Bericht excluding the long _id stuff. Sample output:
[ { name: 'Hans', mail: 'hans#wurst.de', betreff: 'I lost my wurst', inhalt: 'look at me, I am amazing' } ]
That's just one, normally there would be a huge amount of data.
The idea is right now to extract only the name into a string like "Hans". I want to get this name into a var, but hell it seems impossible!
I've tried
Bericht.find(
{},
{ '_id': 0},
function(err, docs) {
if (!err){
console.log(docs.name);
// process.exit();
}
else { throw err;}
}
);
But the I get only "undefined" delivered. I appreciate your help!
Take a look at Mongoose QueryStreams. I haven't used it myself, but I've modified their example code to fit your Model, to give you an idea of how it might work in practice:
var stream = Bericht.find().stream()
, names = []
, i;
function closeHandler() {
console.log(JSON.stringify(names));
};
stream.on('data', function (doc) {
if (doc.name) {
names.push(doc.name);
}
})
stream.on('error', function (err) {
// handle err
})
stream.on('close', closeHandler)
Mongoose find return an array of documents so you should try the following:
Bericht.find(
{},
{ '_id': 0},
function(err, docs) {
if (!err){
for(var i=0; i<docs.length; i++)
{
console.log(docs[i].name);
}
// process.exit();
}
else { throw err;}
}
);