I'm using a MEAN stack and with Mongoose. Is there a way to query MongoDB with multiple ids to only return those specific IDs in one query e.g. /api/products/5001,5002,5003
Is this possible or would I need to query each product individually or add an additional attribute to the products and query by that.
Update: To clarify as suggested below I've managed to get it partially working using {'_id': { $in: [5001,5002,5003]} however I'm having problems figuring out how to pass the list from the api url to the find function.
Using Express.js for router
router.get('/list/:ids', controller.showByIDs);
exports.showByIDs = function(req, res) {
Product.find({'_id': { $in: [req.params.ids]}}, function (err, product) {
if(err) { return handleError(res, err); }
if(!product) { return res.send(404); }
return res.json(product);
})
};
Then trying /api/products/list/5001 works however /api/products/list/5001,5002 doesn't. I'm not sure if it's a syntax problem in the url or my router code that needs to change or the controller.
You can use the $in operator to query for multiple values at once:
Products.find({_id: {$in: [5001, 5002, 5003]}}, function (err, products) { ... });
On the Express side, you need to use a format for the ids parameter that lets you split it into an array of id values, like you had in your first example:
/api/products/5001,5002,5003
Then in your route handler, you can call the split function on the req.params.ids string to turn it into an array of id values that you can use with $in:
exports.showByIDs = function(req, res) {
var ids = req.params.ids.split(',');
Product.find({'_id': { $in: ids}}, function (err, product) {
if(err) { return handleError(res, err); }
if(!product) { return res.send(404); }
return res.json(product);
})
};
Related
I'm trying to return create a paginated list. I used graphql to query the data. With my query, I pass the number of records I need (In a variable named first) and the ID of the last fetched record (In a varible called after). Now I managed to write a query (Note that I used mongoose) to fetch the records. Now what I need to do is get the relavant information to perform the pagination like hasNextPage, hasPreviousPage, currentPage and totalPages.
To get most of these information I need to get the total number of records in the database. To do that I need to send another db request.
I also need to know the position of the record in the table. No idea how.
Here's the query:
new Promise((resolve, reject) =>
Company.where('_id')
.gt(after)
.limit(first)
.lean()
.exec((error, doc) => {
if (error) {
reject(error);
}
resolve({
edges: doc,
pageInfo: {
hasNextPage: '...',
hasPreviousPage: '...',
currentPage: '...',
totalPages: '...'
}
});
}))
Any idea how to do this efficiently?
you can try this module mongoose-paginate
here what i uses, for pagination,
var current = req.query.filter.current;
var limit = req.query.filter.limit;
console.log('params.query.filter.current',current);
var skip = Number(limit)*Number(current)-Number(limit);
console.log('skip::',skip);
Cours.find({'attributes.version.status': true}).skip(skip).limit(limit).sort({_id:'asc'}).exec(function (err, resulta) {
if (err) {
console.log('erreur trouverCours');
res.json({
protecteds: err
});
}
console.log('cours ::', resulta);
res.json({
"data": resulta
});
});
I am sending a query to mongoDB using mongoose. The collection is named Step. I want the result of this query to be an array of _id values, one per step. Currently I am getting all of the step objects in their entirety, because req.query isn't defined in this case.
service:
this.getSteps = function() {
return $http({
method: 'GET',
url: '/api/step'
})
.then(function(response) {
return response.data;
});
};
controller:
readStep: function (req, res) {
Step.find(req.query, function(err, result) {
if (err) {
res.status(500).send(err);
}
res.status(200).send(result);
});
}
Set the second parameter of the find query to '_id' to retrieve only the _id of the objects.
Step.find(req.query, '_id', function(err, result) {
This will return data like this:
[{_id: 123}, {_id: 234}]
If you want to get an array of the Step ids on their own, use the javascript map function like so
result = result.map(function(doc) {
return doc._id;
});
which will give you an array like this:
[123, 234]
You'll need to use query.select, something like as shown below:
Step.find(query).select({ "_id": 1}).then(....);
I'm not able to type much because I'm responding from my handheld.
Hope this help!
I am trying to fetch all the records but with selected fields, I have tried the following ways but none works:
Post.find(
{
where: {},
select: ['title']
}
);
Post.find(
{},
{
fields: {
title: 1
}
}
);
As this answer points out, the fields param "WILL work as long as you pass other params with it such as limit or order."
Alternatively, if you want this throughout your application, you could define a custom toJSON function for your model, under attributes. If not, you could still define it under some other (e.g. filter) and use map to return the custom objects instead of the default model. Remember to take care of the control flow while using map though. Use async/promises/raw logic to avoid returning before all objects are processed.
The issue has been resolved in sails-mongo latest version:
https://github.com/balderdashy/waterline/issues/1098
Thanks
I've played with trying to get above answer to use limit or order to kick in the projection to no avail.
I did see this in the docs located here:
http://sailsjs.org/documentation/reference/waterline-orm/models/native
With an out of the box solution for exactly what you're doing (pasted here for ease of use).
Pet.native(function(err, collection) {
if (err) return res.serverError(err);
collection.find({}, {
name: true
}).toArray(function (err, results) {
if (err) return res.serverError(err);
return res.ok(results);
});
});
Swap out the response base things and change Pet to Post and, this ought to work in the sails console:
Post.native(function(err, collection) {
if (err) throw new Error(err);
collection.find({}, {
title: true
}).toArray(function (err, results) {
if (err) throw new Error(err);
console.log(results);
});
});
You'll still get the _id field, and if you don't want that then hit the Mongo docs on not getting those hint(title: true, _id: false)hint
Hope this helps!
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);
});