I'm trying to modify multiple documents with findAndModify, and then return the new Documents modified.
My query is:
db.users.findAndModify({
query: {
_id: {
$in: [
ObjectId("54061f3c27afac4b44688c1d"),
ObjectId("54061f3c27afac4b44688c1e")
]
}
},
update: {
$inc: {
i: 1
}
},
new: true
});
but can retrieve only one document. My aim is to modify multi documents, and return all of them. Is it possible to retrieve an array of documents?
As explained in this page in the documents, findAndModify "modifies and returns a single document". If you want to modify multiple documents using findAndModify you will have to run it once per document. In the mongo shell, you can achieve that with some JavaScript like the following:
var oids = [ObjectId("54061f3c27afac4b44688c1d"),
ObjectId("54061f3c27afac4b44688c1e")];
docs = [];
for (var i in oids) {
id = oids[i];
doc = db.e.findAndModify({
"query": { "_id": id },
"update": { "$inc": { "i": 1 }},
"new": true
});
docs.push(doc);
}
printjson(docs);
The other option would be to run update using multi as an option and then retrieve the documents. Your code would look something like the following:
db.users.update(
{ "_id": {
"$in": [ObjectId("54061f3c27afac4b44688c1d"),
ObjectId("54061f3c27afac4b44688c1e")]
}
},
{ "$inc": { "i": 1 }},
{ "multi": true }
);
db.users.find(
{ "_id": {
"$in": [ObjectId("54061f3c27afac4b44688c1d"),
ObjectId("54061f3c27afac4b44688c1e")]
}
}
);
Related
i have a collection with more then 1000 documents and there are some documents with same value in some fields, i need to get those
the collection is:
[{_id,fields1,fields2,fields3,etc...}]
what query can i use to get all the elements that have the same 3 fields for example:
[
{_id:1,fields1:'a',fields2:1,fields3:'z'},
{_id:2,fields1:'a',fields2:1,fields3:'z'},
{_id:3,fields1:'f',fields2:2,fields3:'g'},
{_id:4,fields1:'f',fields2:2,fields3:'g'},
{_id:5,fields1:'j',fields2:3,fields3:'g'},
]
i need to get
[
{_id:2,fields1:'a',fields2:1,fields3:'z'},
{_id:4,fields1:'f',fields2:2,fields3:'g'},
]
in this way i can easly get a list of "duplicate" that i can delete if needed, it's not really important get id 2 and 4 or 1 and 3
but 5 would never be included as it's not 'duplicated'
EDIT:
sorry but i forgot to mention that there are some document with null value i need to exclude those
This is the perfect use case of window field. You can use $setWindowFields to compute $rank in the grouping/partition you want. Then, get those rank not equal to 1 to get the duplicates.
db.collection.aggregate([
{
$match: {
fields1: {
$ne: null
},
fields2: {
$ne: null
},
fields3: {
$ne: null
}
}
},
{
"$setWindowFields": {
"partitionBy": {
fields1: "$fields1",
fields2: "$fields2",
fields3: "$fields3"
},
"sortBy": {
"_id": 1
},
"output": {
"duplicateRank": {
"$rank": {}
}
}
}
},
{
$match: {
duplicateRank: {
$ne: 1
}
}
},
{
$unset: "duplicateRank"
}
])
Mongo Playground
I think you can try this aggregation query:
First group by the feilds you want to know if there are multiple values.
It creates an array with the _ids that are repeated.
Then get only where there is more than one ($match).
And last project to get the desired output. I've used the first _id found.
db.collection.aggregate([
{
"$group": {
"_id": {
"fields1": "$fields1",
"fields2": "$fields2",
"fields3": "$fields3"
},
"duplicatesIds": {
"$push": "$_id"
}
}
},
{
"$match": {
"$expr": {
"$gt": [
{
"$size": "$duplicatesIds"
},
1
]
}
}
},
{
"$project": {
"_id": {
"$arrayElemAt": [
"$duplicatesIds",
0
]
},
"fields1": "$_id.fields1",
"fields2": "$_id.fields3",
"fields3": "$_id.fields2"
}
}
])
Example here
I have a collection tblTesting with records saved like
{
"_id": ObjectId("5de9f044af647f21780056e1"),
"name": "abc",
"creditAccountDetails": {
"creditAccountNumber": "0200040671890190",
"creditAccountNumberId": "5db2efb5590a065abc006b12"
}
}
The embedded document "creditAccountDetails" has been wrongly saved. Now I am trying to update them by using mongodb command like
db.tblTesting.updateMany
{},
[
{ $set: { creditAccountDetails: [[ 'creditAccountNumberId' : ObjectId ($creditAccountNumber) ]] } },
{}
]
)
Basically I want that the command should be able to update all the records like
{
"_id": ObjectId("5de9f044af647f21780056e1"),
"name": "abc",
"creditAccountDetails":[ {
"creditAccountNumber": "0200040671890190",
"creditAccountNumberId": ObjectId("5db2efb5590a065abc006b12")
}
]
}
Please help!!!
Note that I am using mongo db 4.0
Since you are on mongodb version 4.0, which does not allow referring document fields in an update. A way to do this is iterate via cursor on the collection and update the field.
var cursor = db.collection.find({});
while (cursor.hasNext()) {
var doc = cursor.next();
db.collection.updateOne(
{
_id: doc._id
},
{
$set: {
creditAccountDetails: [
{
creditAccountNumber: doc.creditAccountDetails.creditAccountNumber,
creditAccountNumberId: ObjectId(
doc.creditAccountDetails.creditAccountNumberId
)
}
]
}
}
);
}
For readers who are on Mongodb 4.2.0+ which allows using aggregation pipeline ops in update methods updateOne, updateMany where document fields can be used as part of $set.
db.collection.updateMany({}, [
{
$set: {
creditAccountDetails: [
{
creditAccountNumber: "$creditAccountDetails.creditAccountNumber",
creditAccountNumberId: {
$toObjectId: "$creditAccountDetails.creditAccountNumberId"
}
}
]
}
}
]);
tblTesting's schema should have define type ObjectId for creditAccountNumberId
below example I used mongoose
const tblTesting = mongoose.Schema({
....
creditAccountNumberId: {
type: mongoose.Schema.Types.ObjectId,
},
....
}, {
collection: 'tblTesting',
timestamps: true,
strict: false,
})
I am trying to update multiple sub documents by given array of sub documents id's. I tried multiple approaches but it's not working.
In my scenario i need to update multiple sub documents by given array of id's. Here is my query as below:
Approach 1. (No elements were updating)
var updated = await ModelName.update(
{
'subDocArray._id' : { $in: req.body.elementId }
},
{
$set: {
'subDocArray.$[elem].abc': req.body.abcValue,
'subDocArray.$[elem].xyz': req.body.xyzValue
},
},{ "arrayFilters": [{ "elem._id": { $in: req.body.elementId } }], "multi": true, "upsert": true }
).lean().exec();
Approach 2: (Only First occurred element is updating)
var updated = await ModelName.update(
{
'subDocArray._id' : { $in: req.body.elementId }
},
{
$set: {
'subDocArray.$.abc': req.body.abcValue,
'subDocArray.$.xyz': req.body.xyzValue
},
},{ multi: true}
).exec();
Here req.body.elementId is array of sub doc id's.
Approach 1 was almost right. I was passing array of elementId's are which are in string format so i converted them in ObjectId form and then it works.
var arrOfObjectId = [];
req.body.elementId.forEach(elem => {
arrOfObjectId.push(Types.ObjectId(elem))
});
To find the difference between both of the array i printed both in console which were showing like below:
console.log(req.body.elementId)
Result: ['xxxxxxxxxxxxxxxxxxxxxxxx','yyyyyyyyyyyyyyyyyyyyyyyy'] //WRONG
console.log(arrOfObjectId)
Result: [ObjectId('xxxxxxxxxxxxxxxxxxxxxxxx'),ObjectId('yyyyyyyyyyyyyyyyyyyyyyyy')] //RIGHT
var updated = await ModelName.update(
{
'subDocArray._id' : { $in: arrOfObjectId }
},
{
$set: {
'subDocArray.$[elem].abc': req.body.abcValue,
'subDocArray.$[elem].xyz': req.body.xyzValue
},
},{ "arrayFilters": [{ "elem._id": { $in: arrOfObjectId } }], "multi": true, "upsert": true }
).lean().exec();
This query is doing the job fine :
db.collection.update(
{ "_id": oneIdProvided },
{ $inc: { "field": 5 } },{ upsert: true }
)
Now I would like to do the same operation multiple time with different IDs, I thought the good way was to use $in and therefore I tried :
db.collection.update(
{ "_id": { $in: oneArrayOfIds} },
{ $inc: { "field": 5 } },{ upsert: true }
)
Problem is : if one of the provided ID in the array is not existing in the collection, a new document is created (which is what I want) but will be attributed an automatic ID, not using the ID I provided and was looking for.
One solution I see could be to do first an insert query with my array of ID (those already existing would not be modified) and then doing my update query with upsert: false
Do you see a way of doing that in only one query ?
We can do this by performing multiple write operations using the bulkWrite() method.
function* range(start, end, step) {
for (let val=start; val<end; val+=step)
yield val
}
let oneArrayOfIds; // For example [1, 2, 3, 4]
let bulkOp = oneArrayOfIds.map( id => {
return {
"updateOne": {
"filter": { "_id": id },
"update": { "$set": { "field": 5 } },
"upsert": true
}
};
});
const limit = 1000;
const len = bulkOp.length;
let chunks = [];
if (len > 1000) {
for (let index of range(0, len, limit)) {
db.collection.bulkWrite(bulkOp.slice(index, index+limit));
}
} else {
db.collection.bulkWrite(bulkOp);
}
Here is a doc I have:
var docIHave = {
_id: "someId",
things: [
{
name: "thing1",
stuff: [1,2,3,4,5,6,7,8,9]
},
{
name: "thing2",
stuff: [4,5,6,7,8,9,10,11,12,13,14]
},
{
name: "thing3",
stuff: [1,4,6,8,11,21,23,30]
}
]
}
This is the doc I want:
var docIWant = {
_id: "someId",
things: [
{
name: "thing1",
stuff: [5,6,7,8,9]
},
{
name: "thing2",
stuff: [5,6,7,8,9,10,11]
},
{
name: "thing3",
stuff: [6,8,11]
}
]
}
stuff´s of docIWant should only contain items greater than min=4
and smaller than max=12.
Background:
I have a meteor app and I subscribe to a collection giving me docIHave. Based on parameters min and max I need the docIWant "on the fly". The original document should not be modified. I need a query or procedure that returns me docIWant with the subset of stuff.
A practical code example would be greatly appreciated.
Use the aggregation framework for this. In the aggregation pipeline, consider the $match operator as your first pipeline stage. This is quite necessary to optimize your aggregation as you would need to filter documents that match the given criteria first before passing them on further down the pipeline.
Next use the $unwind operator. This deconstructs the things array field from the input documents to output a document for each element. Each output document is the input document with the value of the array field replaced by the element.
Another $unwind operation would be needed on the things.stuff array as well.
The next pipeline stage would then filter dopcuments where the deconstructed things.stuff match the given min and max criteria. Use a $match operator for this.
A $group operator is then required to group the input documents by a specified identifier expression and applies the accumulator expression $push to each group. This creates an array expression to each group.
Typically your aggregation should end up like this (although I haven't actually tested it but this should get you going in the right direction):
db.collection.aggregate([
{
"$match": {
"things.stuff": { "$gt": 4, "$lte": 11 }
}
},
{
"$unwind": "$things"
},
{
"$unwind": "$things.stuff"
},
{
"$match": {
"things.stuff": { "$gt": 4, "$lte": 11 }
}
},
{
"$group": {
"_id": {
"_id": "$_id",
"things": "$things"
},
"stuff": {
"$push": "$things.stuff"
}
}
},
{
"$group": {
"_id": "$_id._id",
"things": {
"$push": {
"name": "$_id.things.name",
"stuff": "$stuff"
}
}
}
}
])
If you need to transform the document on the client for display purposes, you could do something like this:
Template.myTemplate.helpers({
transformedDoc: function() {
// get the bounds - maybe these are stored in session vars
var min = Session.get('min');
var max = Session.get('max');
// fetch the doc somehow that needs to be transformed
var doc = SomeCollection.findOne();
// transform the thing.stuff arrays
_.each(doc.things, function(thing) {
thing.stuff = _.reject(thing.stuff, function(n) {
return (n < min) || (n > max);
});
});
// return the transformed doc
return doc;
}
});
Then in your template: {{#each transformedDoc.things}}...{{/each}}
Use mongo aggregation like following :
First use $unwind this will unwind stuff and then use $match to find elements greater than 4. After that $group data based on things.name and add required fields in $project.
The query will be as following:
db.collection.aggregate([
{
$unwind: "$things"
}, {
$unwind: "$things.stuff"
}, {
$match: {
"things.stuff": {
$gt: 4,
$lt:12
}
}
}, {
$group: {
"_id": "$things.name",
"stuff": {
$push: "$things.stuff"
}
}
}, {
$project: {
"thingName": "$_id",
"stuff": 1
}
}])