When I updated document and I need a updated document
const updateMe = await Friends.updateOne(
{
userId: req.user._id,
"friends._id": req.params.id,
},
{
$set: { "friends.$.status": "added" },
},
{ returnDocument: "after" }
);
console.log(updateMe);
But it s returning that
{
acknowledged: true,
modifiedCount: 0,
upsertedId: null,
upsertedCount: 0,
matchedCount: 0
}
How can I get it?
I recommend that you use findOneAndUpdate because it has the option to get the updated document.
Example from mongo docs
db.students2.findOneAndUpdate(
{ _id : 1 },
[ { $set: { "total" : { $sum: "$grades.grade" } } } ], // The $set stage is
an alias for ``$addFields`` stage
{ returnNewDocument: true }
)
MongoDb findOneAndUpdate Documentation
Related
I'm performing a MongoDB query to update a document like below -
await this.activity.findOneAndUpdate(
{ _id: activityId },
{
$set: { isFlagged: //boolean_value },
},
);
In the update part of this query, is there a way to get the matched document from the previous step?
Basically, to do something like this -
const data = await this.activity.findOne({_id: activityId})
await this.activity.findOneAndUpdate(
{ _id: activityId },
{
$set: { isFlagged: !data.isFlagged }, //toggle between the previous boolean value
},
);
Is there a way to achieve this in a single query?
Use $not in an update with aggregation pipeline.
db.collection.update({
"activityId": 1
},
[
{
$set: {
isFlagged: {
$not: "$isFlagged"
}
}
}
])
Mongo Playground
I have such a schema:
doc:
{
//Some fields
visits:
[
{
userID: Int32
time: Int64
}
]
}
I want to first check if a specific userID exists, if not, push a document with that userID and system time, else just update time value. I know neither $push nor $addToSet are not able to do that. Also using $ with upsert:true doesn't work, because of official documentation advice which says DB will use $ as field name instead of operator when trying to upsert.
Please guide me about this. Thanks
You can use $addToSet to add an item to the array and $set to update an existing item in this array.
The following will add a new item to the array if the userID is not found in the array :
db.doc.update({
visits: {
"$not": {
"$elemMatch": {
"userID": 4
}
}
}
}, {
$addToSet: {
visits: {
"userID": 4,
"time": 1482607614
}
}
}, { multi: true });
The following will update the subdocument array item if it matches the userId :
db.doc.update({ "visits.userID": 2 }, {
$set: {
"visits.$.time": 1482607614
}
}, { multi: true });
const p = await Transaction.findOneAndUpdate(
{
_id: data.id,
'products.id': { $nin: [product.id] },
},
{
$inc: {
actualCost: product.mrp,
},
$push: {
products: { id: product.id },
},
},
{ new: true }
);
or
db.collection.aggregate([
{
"$match": {
"_id": 1
}
},
{
"$match": {
"sizes.id": {
"$nin": [
7
]
}
}
},
{
"$set": {
"price": 20
}
}
])
https://mongoplayground.net/p/BguFa6E9Tra
I know it's very late. But it may help others. Starting from mongo4.4, we can use $function to use a custom function to implement our own logic. Also, we can use the bulk operation to achieve this output.
Assuming the existing data is as below
{
"_id" : ObjectId("62de4e31daa9b8acd56656ba"),
"entrance" : "Entrance1",
"visits" : [
{
"userId" : 1,
"time" : 1658736074
},
{
"userId" : 2,
"time" : 1658736671
}
]
}
Solution 1: using custom function
db.visitors.updateMany(
{_id: ObjectId('62de4e31daa9b8acd56656ba')},
[
{
$set: {
visits: {
$function: {
lang: "js",
args: ["$visits"],
body: function(visits) {
let v = []
let input = {userId: 3, time: Math.floor(Date.now() / 1000)};
if(Array.isArray(visits)) {
v = visits.filter(x => x.userId != input.userId)
}
v.push(input)
return v;
}
}
}
}
}
]
)
In NodeJS, the function body should be enclosed with ` character
...
lang: 'js',
args: ["$visits"],
body: `function(visits) {
let v = []
let input = {userId: 3, time: Math.floor(Date.now() / 1000)};
if(Array.isArray(visits)) {
v = visits.filter(x => x.userId != input.userId)
}
v.push(input)
return v;
}`
...
Solution 2: Using bulk operation:
Please note that the time here will be in the ISODate
var bulkOp = db.visitors.initializeOrderedBulkOp()
bulkOp.find({ _id: ObjectId('62de4e31daa9b8acd56656ba') }).updateOne({$pull: { visits: { userId: 2 }} });
bulkOp.find({ _id: ObjectId('62de4e31daa9b8acd56656ba') }).updateOne({$push: {visits: {userId: 2, time: new Date()}}})
bulkOp.execute()
Reference link
I tried searching on here but couldn't really find what I need. I have documents like this:
{
appletype:Granny,
color:Green,
datePicked:2015-01-26,
dateRipe:2015-01-24,
numPicked:3
},
{
appletype:Granny,
color:Green,
datePicked:2015-01-01,
dateRipe:2014-12-28,
numPicked:6
}
I would like to return only those apples picked latest, will all fields. I want my query to return me the first document only essentially. When I try to do:
db.collection.aggregate([
{ $match : { "appletype" : "Granny" } },
{ $sort : { "datePicked" : 1 } },
{ $group : { "_id" : { "appletype" : "$appletype" },
"datePicked" : { $max : "$datePicked" } },
])
It does return me all the apples picked latest, however with only appletype:Granny and datePicked:2015-01-26. I need the remaining fields. I tries using $project and adding all the fields, but it didn't get me what I needed. Also, when I added the other fields to the group, since datePicked is unique, it returned both records.
How can I go about returning all fields, for only the latest datePicked?
Thanks!
From your description, it sounds like you want one document for each of the types of apple in your collection and showing the document with the most recent datePicked value.
Here is an aggregate query for that:
db.collection.aggregate([
{ $sort: { "datePicked": -1 },
{ $group: { _id: "$appletype", color: { $first: "$color" }, datePicked: { $first: "$datePicked" }, dateRipe: { $first: "$dateRipe" }, numPicked: { $first: "$numPicked" } } },
{ $project: { _id: 0, color: 1, datePicked: 1, dateRipe: 1, numPicked: 1, appletype: "$_id" } }
])
But then based on the aggregate query you've written, it looks like you're trying to get this:
db.collection.find({appletype: "Granny"}).sort({datePicked: -1}).limit(1);
I have a collection with documents like below:
{
title: "whatever",
answers: [
{id: 10, question: ObjectId("54380350a52147000aad4e9b")},
{id: 13, question: ObjectId("54380350a52147000aad4e9c")},
{id: 33}
]
}
I'm have attempted to unset the question attribute using the commands below:
db.participants.update({}, {$unset: {"answers.question": ""}}, {upsert: false, multi:true} )
and
db.participants.update({}, {$unset: {"answers.question": 1}}, {upsert: false, multi:true} )
Both of these spit out: WriteResult({ "nMatched" : 628795, "nUpserted" : 0, "nModified" : 0 }) when completed, but no documents are updated (as the message suggests). Any idea why my update isn't working?
Your update is not working because answers is an array. So you should use the positional operator:
db.participants.update({ 'answers.question': { $exists: true } }, { $unset: { 'answers.$.question': '' } }, { upsert: false, multi: true });
However it updates only one item in the array. This is a limitation of MongoDB, see SERVER-1243.
You can use a forEach to iterate through the items of the array:
db.eval(function () {
db.participants.find({ 'answers.question': { $exists: true } }).forEach(function (participant) {
participant.answers.forEach(function (answer) {
delete answer.question;
});
db.participants.update({ _id: participant._id }, { $set: { answers: participant.answers } });
});
});
I have the following documents:
[{
"_id":1,
"name":"john",
"position":1
},
{"_id":2,
"name":"bob",
"position":2
},
{"_id":3,
"name":"tom",
"position":3
}]
In the UI a user can change position of items(eg moving Bob to first position, john gets position 2, tom - position 3).
Is there any way to update all positions in all documents at once?
You can not update two documents at once with a MongoDB query. You will always have to do that in two queries. You can of course set a value of a field to the same value, or increment with the same number, but you can not do two distinct updates in MongoDB with the same query.
You can use db.collection.bulkWrite() to perform multiple operations in bulk. It has been available since 3.2.
It is possible to perform operations out of order to increase performance.
From mongodb 4.2 you can do using pipeline in update using $set operator
there are many ways possible now due to many operators in aggregation pipeline though I am providing one of them
exports.updateDisplayOrder = async keyValPairArr => {
try {
let data = await ContestModel.collection.update(
{ _id: { $in: keyValPairArr.map(o => o.id) } },
[{
$set: {
displayOrder: {
$let: {
vars: { obj: { $arrayElemAt: [{ $filter: { input: keyValPairArr, as: "kvpa", cond: { $eq: ["$$kvpa.id", "$_id"] } } }, 0] } },
in:"$$obj.displayOrder"
}
}
}
}],
{ runValidators: true, multi: true }
)
return data;
} catch (error) {
throw error;
}
}
example key val pair is: [{"id":"5e7643d436963c21f14582ee","displayOrder":9}, {"id":"5e7643e736963c21f14582ef","displayOrder":4}]
Since MongoDB 4.2 update can accept aggregation pipeline as second argument, allowing modification of multiple documents based on their data.
See https://docs.mongodb.com/manual/reference/method/db.collection.update/#modify-a-field-using-the-values-of-the-other-fields-in-the-document
Excerpt from documentation:
Modify a Field Using the Values of the Other Fields in the Document
Create a members collection with the following documents:
db.members.insertMany([
{ "_id" : 1, "member" : "abc123", "status" : "A", "points" : 2, "misc1" : "note to self: confirm status", "misc2" : "Need to activate", "lastUpdate" : ISODate("2019-01-01T00:00:00Z") },
{ "_id" : 2, "member" : "xyz123", "status" : "A", "points" : 60, "misc1" : "reminder: ping me at 100pts", "misc2" : "Some random comment", "lastUpdate" : ISODate("2019-01-01T00:00:00Z") }
])
Assume that instead of separate misc1 and misc2 fields, you want to gather these into a new comments field. The following update operation uses an aggregation pipeline to:
add the new comments field and set the lastUpdate field.
remove the misc1 and misc2 fields for all documents in the collection.
db.members.update(
{ },
[
{ $set: { status: "Modified", comments: [ "$misc1", "$misc2" ], lastUpdate: "$$NOW" } },
{ $unset: [ "misc1", "misc2" ] }
],
{ multi: true }
)
Suppose after updating your position your array will looks like
const objectToUpdate = [{
"_id":1,
"name":"john",
"position":2
},
{
"_id":2,
"name":"bob",
"position":1
},
{
"_id":3,
"name":"tom",
"position":3
}].map( eachObj => {
return {
updateOne: {
filter: { _id: eachObj._id },
update: { name: eachObj.name, position: eachObj.position }
}
}
})
YourModelName.bulkWrite(objectToUpdate,
{ ordered: false }
).then((result) => {
console.log(result);
}).catch(err=>{
console.log(err.result.result.writeErrors[0].err.op.q);
})
It will update all position with different value.
Note : I have used here ordered : false for better performance.