In express and mongodb I want delete document by id
findOneAndDelete() Can not delete by _id, can only delete by field ! why ?
db.collection('quotes').findOneAndDelete({name: req.body.name}, (err, result) => {
if (err) return res.send(500, err)
})
var ObjectId = require('mongodb').ObjectId;
var collection = db.collection('quotes');
collection.remove({_id: new ObjectId(req.body.id)}, function(err, result) {
if (err) {
console.log(err);
} else {
res.send('A darth vadar quote got deleted')
}
});
var mongodb = require('mongodb');
db.collection('quotes', function(err, collection) {
collection.deleteOne({_id: new mongodb.ObjectID(req.body.id)});
});
Difference of three functions?
In short:
findOneAndDelete() returns the deleted document after having deleted it (in case you need its contents after the delete operation);
deleteOne() is used to delete a single document
remove() is a deprecated function and has been replaced by deleteOne() (to delete a single document) and deleteMany() (to delete multiple documents)
findOneAndDelete() should be able to delete on _id.
Related
I need to declare my mongodb collections as variables, however when I try to log them the array comes out as empty, the collection is definitely full as I have checked on the mongodb shell. This is an example of one of the collections I'm trying to declare.
if (Pizza.length === 0) {Pizza.insertMany(defaultpizzasCollectionItems, function(err){
if (err) {
console.log(err);
}
else {
console.log("Pizzas saved!");
}
})
Pizza.find({}, function(err, pizzas){
let foundPizzas = pizzas;
})
let foundPizzas = [];
console.log(foundPizzas);
What am I doing wrong?
I am writing a service class (mongo_service.js) in order to keep my CRUD operations seperate for a project.
Below is the code to update multiple items.
updateMultipleCollection(Model, searchObject, collectionNewToUpdate) {
return new Promise(function (resolve, reject) {
Model.update( searchObject, collectionNewToUpdate, {new:true, multi:true}, function (err, data) {
if (err) {
reject(err);
}
resolve (data);
console.info("Multiple updates successful");
});
});
};
This works fine but the promise won't return the updated objects and I was wondering whether there was any other way to overcome this??
NOTE: In mongoose documentation they have mentioned that .update() will not return the updated objects whereas .findOneAndUpdate() does.
you could do a .find() and that will return an array.
Then do a forEach over the array and do .save on each doc. The new doc should be in the callback of .save
router.get('/wiki/:topicname', function(req, res, next) {
var topicname = req.params.topicname;
console.log(topicname);
summary.wikitext(topicname, function(err, result) {
if (err) {
return res.send(err);
}
if (!result) {
return res.send('No article found');
}
$ = cheerio.load(result);
var db = req.db;
var collection = db.get('try1');
collection.insert({ "topicname" : topicname, "content": result }, function (err, doc){
if (err) {
// If it failed, return error
res.send("There was a problem adding the information to the database.");
}
else {
// And forward to success page
res.send("Added succesfully");
}
});
});
Using this code, I am trying to add the fetched content from Wikipedia in to the collection try1. The message "Added succesfully" is displayed. But the collection seems to be empty. The data is not inserted in the database
The data must be there, mongodb has { w: 1, j: true } write concern options by default so its only returns without an error if the document is truly inserted if there were any document to insert.
Things you should consider:
-Do NOT use insert function, its depricated use insertOne, insertMany or bulkWrite. ref.: http://mongodb.github.io/node-mongodb-native/2.1/api/Collection.html#insert
-The insert methods callback has two parameters. Error if there was an error, and result. The result object has several properties with could be used for after insert result testing like: result.insertedCount will return the number of inserted documents.
So according to these in your code you only test for error but you can insert zero documents without an error.
Also its not clear to me where do you get your database name from. Is the following correct in your code? Are you sure you are connected to the database you want to use?
var db = req.db;
Also you don't have to enclose your property names with " in your insert method. The insert should look something like this:
col.insertOne({topicname : topicname, content: result}, function(err, r) {
if (err){
console.log(err);
} else {
console.log(r.insertedCount);
}
});
Start your mongod server in a correct path,i.e, same path as that of what you are using to check the contents of collection.
sudo mongod --dbpath <actual-path>
All the examples I have seen for MongoDb & Mongoskin for update, have individual properties being updated, like so:
// this works when I specify the properties
db.collection('User').update({_id: mongoskin.helper.toObjectID(user._id)},
{'$set':{displayName:user.displayName}}, function(err, result) {
if (err) throw err;
if (result){ res.send(result)}
});
But what if I wanted the whole object/document to be updated instead:
// this does not appear to work
db.collection('User').update({_id: mongoskin.helper.toObjectID(user._id)}, {'$set':user},
function(err, result){
// do something
}
It returns the error:
// It appears Mongo does not like the _id as part of the update
MongoError: After applying the update to the document {_id: ObjectId('.....
To overcome this issue, this is what I had to do to make things work:
function (req, res) {
var userId = req.body.user._id
var user = req.body.user;
delete user._id;
db.collection('User').update({_id: mongoskin.helper.toObjectID(userId)},
{'$set':user}, function(err, result) {
if (err) throw err;
console.log('result: ' + result)
if (result){ res.send(result)}
});
})
It there a more elegant way of updating the whole document, instead of hacking it with:
delete user._id
If you want to update the whole object, you do not need a $set. I am not aware of mongoskin, but in shell you would do something like:
var userObj = {
_id: <something>
...
};
db.user.update({_id: user._id}, user);
Which I think can be translated in your mongoskin in the following way.
db.collection('User').update({_id: user._id}, user, function(){...})
But here is the problem. You can not update _id of the element in Mongo. And this is what your error tells you. So you can remove the _id from your user object and have it separately. Search by this separate _id and update with a user object without _id.
I have a list of mongo '_id' which I want to delete. Currently I am doing this
# inactive_users --> list of inactive users
for item in inactive_users:
db.users.remove({'_id' : item})
but my problem is the list is too huge... (it might go 100,000 +). So querying for every item in list will only increase the load on server. Is their a way to pass the entire list in mongo query so that I dont have to fire query again and again.
Thank you
db.users.deleteMany({'_id':{'$in':inactive_users}})
List them all and use $in operator:
db.users.remove({_id:{$in:[id1, id2, id3, ... ]}})
You need to pass the ids in a specific format using ObjectId():
db.users.remove({_id: {$in: [ObjectId('Item1'), ObjectId('Item2'), ObjectId('Item2')]}});
Remove doesn't accept integer - you have to use ObjectId instance with _id format as a string.
var collection = db.users;
var usersDelete = [];
var ObjectID = req.mongo.ObjectID; //req is request from express
req.body.forEach(function(item){ //req.body => [{'_id' : ".." , "name" : "john"}]
usersDelete.push(new ObjectID(item._id));
});
collection.remove({'_id':{'$in': usersDelete}},function(){
//res.json(contatos);
});
I had the same question and ran across these answers but it seems the MongoDB manual is recommending deleteMany instead of remove. deleteMany returns the delete count as well as an acknowledgement of the write concern (if the operation succeeded).
const ids = [id1, id2, id3...];
const query = { _id: { $in: ids} };
dbo.collection("users").deleteMany(query, function (err, obj) {
if (err) throw err;
});
Or with an arrow function:
const ids = [id1, id2, id3...];
const query = { _id: { $in: ids} };
dbo.collection("users").deleteMany(query, (err, obj) => {
if (err) throw err;
});
Or better yet, with a promise:
const ids = [id1, id2, id3...];
const query = { _id: { $in: ids} };
dbo.collection("users").deleteMany(query)
.then(result => {
console.log("Records Deleted");
console.log(JSON.stringify(result));
//for number removed...
console.log("Removed: " + result["n"]);
})
.catch(err => {
console.log("Error");
console.log(err);
});