I'm looking to move an array of subdocuments into a collection of it's own keyed by the owner id. Currently, my collection is formed like this:
"_id": ObjectId("123"),
"username": "Bob Dole",
"logins": [{
"_id": ObjectId("abc123"),
"date": ISODate("2016")
}, {
"_id": ObjectId("def456"),
"date": ISODate("2016")
}]
I'm looking for the best way to write a script that would loop over each user, and move each item in the logins array to it's own "logins" collection, as follows:
{
"_id": ObjectId("abc123"),
"_ownerId": ObjectId("123"),
"date": ISODate("2016")
}
{
"_id": ObjectId("def567"),
"_ownerId": ObjectId("123"),
"date": ISODate("2016")
}
When the script ends, I'd like the login array to be removed entirely from all users.
this query will create new collection using aggregation framework
to see how it looks - just remove $out pipeline phase
db.thinking.aggregate([
{
$unwind:"$logins"
},{
$project:{
_id:"$logins._id",
_ownerId:"$_id",
date:"$logins.date"
}
},
{
$out: "newCollection"
}
])
to delete array records - as suggested in comment:
db.thinking.update({},{ "$unset": { "logins": "" } },{ "multi": true })
Related
I know that by the title it is not very clear what is my problem, so let me explain it with an example.
Let's suppose I have a collection in a mongo database called tweets whose elements look like this:
{
"id": "tweet_id",
"text": "this is the tweet's text",
"user": {
"id": "user_id",
"name": "user_name",
}
}
Let's suppose that we have 100 documents that look like that, and 10 users with diferent ids and names.
How would look a query to know see the different user_id s that exist in the collection and their names?
The result I want would look like this:
{"user_id1": "user_name1"}
{"user_id2": "user_name2"}
...
{"user_id10": "user_name10"}
Thank you for your help
You can use this aggregation query:
First $group by user.id to get all differents user ids with the name.
And then use $replaceRoot with $arrayToObject to get the desired output format.
db.collection.aggregate([
{
"$group": {
"_id": "$user.id",
"name": {
"$first": "$user.name"
}
}
},
{
"$replaceRoot": {
"newRoot": {
"$arrayToObject": [
[
{
"k": "$_id",
"v": "$name"
}
]
]
}
}
}
])
Example here
I am working on a Node.js application that is using a MongoDB database with Mongoose. I've been stuck in this thing and didn't come up with the right query.
Problem:
There is a collection named chats which contain embedded documents (rooms) as an array of objects. I want to delete these embedded documents (rooms) through Ids which are in the array.
{
"_id": "ObjectId(6138e2b55c175846ec1e38c5)",
"type": "bot",
"rooms": [
{
"_id": "ObjectId(6138e2b55c145846ec1e38c5)",
"genre": "action"
},
{
"_id": "ObjectId(6138e2b545c145846ec1e38c5)",
"genre": "adventure"
}
]
},
{
"_id": "ObjectId(6138e2b55c1765846ec1e38c5)",
"type": "person",
"rooms": [
{
"_id": "ObjectId(6138e2565c145846ec1e38c5)",
"genre": "food"
},
{
"_id": "ObjectId(6138e2b5645c145846ec1e38c5)",
"genre": "sport"
}
]
},
{
"_id": "ObjectId(6138e2b55c1765846ec1e38c5)",
"type": "duo",
"rooms": [
{
"_id": "ObjectId(6138e21c145846ec1e38c5)",
"genre": "travel"
},
{
"_id": "ObjectId(6138e35645c145846ec1e38c5)",
"genre": "news"
}
]
}
I am converting my array of ids into MongoDB ObjectId so I can use these ids as match criteria.
const idsRoom = [
'6138e21c145846ec1e38c5',
'6138e2565c145846ec1e38c5',
'6138e2b545c145846ec1e38c5',
];
const objectIdArray = idsRoom.map((s) => mongoose.Types.ObjectId(s));
and using this query for the chat collection. But it is deleting the whole document and I only want to delete the rooms embedded document because the ids array is only for the embedded documents.
Chat.deleteMany({ 'rooms._id': objectIdArray }, function (err) {
console.log('Delete successfully')
})
I really appreciate your help on this issue.
You have to use $pull operator in a update query like this:
This query look for documents where exists the _id into rooms array and use $pull to remove the object from the array.
yourModel.updateMany({
"rooms._id": {
"$in": [
"6138e21c145846ec1e38c5",
"6138e2565c145846ec1e38c5",
"6138e2b545c145846ec1e38c5"
]
}
},
{
"$pull": {
"rooms": {
"_id": {
"$in": [
"6138e21c145846ec1e38c5",
"6138e2565c145846ec1e38c5",
"6138e2b545c145846ec1e38c5"
]
}
}
}
})
Example here.
Also you can run your query without the query parameter (in update queries the first object is the query) like this and result is the same. But is better to indicate mongo the documents using this first object.
I have a collection that consists of objects like this:
{
"name": "Event One",
"user_id": "1"
"rsvp": [
{"id": "1","name":"John Doe","industry":"Software"},
{"id": "2","name":"John Doe II","industry":"Software"},
]
}
I am trying to query all events that a user has rsvp too and that he did not create. Then match the rsvp with the industry the are in. Is it possible to query in mongoDB and have it returned like this:
[
{"id": "1","name":"John Doe"},
{"id": "2","name":"John Doe II"},
]
The query I have is below:
events.find({"$and":[{"rsvp.contact.indusrty":{"$in":["Software","Information Systems"]}},{"user_id":{"$ne":"5d335704802df000076bad97"}}]},{"projection":{"rsvp.contact.name":true},"typeMap":{"root":"array","document":"array"}})
I am new to MONGODB and can't seem to find anything that is helping me figure this out.
You need $match to define filtering criteria, $unwind to get single document per rsvp and $replaceRoot to promote rsvp to root model:
db.events.aggregate([
{
$match: {
"$and":[
{
"rsvp.industry":{
"$in":["Software","Information Systems"]
}
},
{ "user_id":{"$ne":"5d335704802df000076bad97"}}
]
}
},
{
$unwind: "$rsvp"
},
{
$replaceRoot: {
newRoot: "$rsvp"
}
},
{
$project: {
industry: 0
}
}
])
Mongo Playground
I am tracking user IP's by adding them to an array on the user document like so:
{
"_id": "LafnHzmQL6rBmXNxJ",
"name": "someuser",
"displayName": "SomeUser",
"knownIPs": ["1.1.1.1", "2.2.2.2", "3.3.3.3"]
}
How can I find any documents where any 1 of the knownIPs match any 1 of the knownIPs in another (without specifying a particular value) regardless of what the actual IP is.
The goal is to identify people who are using multiple accounts so they can be flagged programmatically for further inspection. I have over 40,000 users, will this be too intensive of an aggregation?
Use the following aggregation pipeline:
db.collection.aggregate([
{ "$unwind": "$knownIPs" },
{
"$group": {
// Group by the IP address
"_id": "$knownIPs",
// Count number of matching docs for the group
"count": { "$sum": 1 },
// Save the _id for matching docs
"docs": { "$push": "$_id" }
}
},
{
"$match": {
"count": { "$gt": 1 }
}
}
])
I think you should use $unwind function on the array of knownIPs. so that it will give you three child object from parent object.
For example:
db.document_name.aggregate( [ { $unwind : "$knownIPs" } ] ) gives you
{
"_id": "LafnHzmQL6rBmXNxJ",
"name": "someuser",
"displayName": "SomeUser",
"knownIPs": "1.1.1.1"
}
{
"_id": "LafnHzmQL6rBmXNxJ",
"name": "someuser",
"displayName": "SomeUser",
"knownIPs": "2.2.2.2"
}
{
"_id": "LafnHzmQL6rBmXNxJ",
"name": "someuser",
"displayName": "SomeUser",
"knownIPs": "3.3.3.3"
}
After unwind operation, perform GroupBy operation on all the objects generated from unwind operation. So it will give the number of users who have same Ip.
I collected followers list and friends list for n number of users from twitter and stored them in mongodb.
Here is a sample document:
{
"_id": ObjectId("561d6f8986a0ea57e51ec95c"),
"status": "True",
"UserId": "1489245878",
"followers": [
"1566382441",
"1155774331"
],
"followersCount": 2,
"friendsCount": 5,
"friends": [
"1135511478",
"998082481",
"565321118",
"848123988",
"343334562"
]
}
I wanted to know within my collection, are there any userids that are also in the followers list of some other documents. Lets say we have user "a", now i would like to know if user "a" is in the followers list of any other document within the same collection. I'm not sure how to do this. In case if we have, i would like to project the userid and the _id of the document that has the userid within the followers list.
I guess you can use aggregate function like below to get this result.
db.getCollection('your_collection").aggregate([
{
"$match": {
"followers": "1566382441"
}
},
{
"$project": {
"followers": 1
}
},
{
"$unwind": "$followers"
},
{
"$match": {
"followers": "1566382441"
}
},
{
"$group": {
"_id": "$followers",
"ids": {
"$addToSet": "$_id"
}
}
},
{
"$project": {
"userId": "$_id",
"ids": 1,
"_id": 0
}
}
])
I am using only a sample of your data. You can add your list of users for whom you are trying to filter in both stages of "$match". Just see if this helps.
P.S: I know its been a long time since you asked this question! But you know, its never late!