how to use update query in mongoDb? - mongodb

I have few documents in user Collection like below .I need to update ancestors field alone,Need to add few more values.
db.users.find()
{
"_id" : ObjectId("5d9fd81f3d598088d2ea5dcc"),
"DOB" : ISODate("1979-05-23T00:00:00Z"),
"userImage" : "sathish_1589780950636.jpeg",
"createdDateTime" : ISODate("2016-02-01T09:43:27Z"),
"modifiedDateTime" : ISODate("2017-04-26T15:57:09Z"),
"status" : "active",
"ancestors" : [
ObjectId("5d9fd81b3d598088d2ea5dc7")
],
"parent" : ObjectId("5d9fd81b3d598088d2ea5dc7")
}
When i tried the below query.
db.users.update({"_id" : ObjectId("5d9fd81f3d598088d2ea5dcc")},{$set:{"ancestors" : [
ObjectId("5f45f9491ff4bd74ec754e3a"),
ObjectId("5d9fd8203d598088d2ea5dcd"),
ObjectId("5d9fd8723d598088d2ea5e43")
]}})
It just replace the old one and completely adding the new one.
I need the result to be like this .old data should also remain and new one should be added.
"ancestors" : [
ObjectId("5f45f9491ff4bd74ec754e3a"),
ObjectId("5d9fd8203d598088d2ea5dcd"),
ObjectId("5d9fd81b3d598088d2ea5dc7"),
ObjectId("5d9fd8723d598088d2ea5e43")
]
This update query should be done in all documents in that collection. the above mentioned 3 values to be added in all documents, instead of find and update, I should be doing bulk updated

I think you can run the following:
db.users.updateOne({"_id" : ObjectId("5d9fd81f3d598088d2ea5dcc")},{$addToSet:{"ancestors" :{ $each: [
ObjectId("5f45f9491ff4bd74ec754e3a"),
ObjectId("5d9fd8203d598088d2ea5dcd"),
ObjectId("5d9fd8723d598088d2ea5e43")
]}}})
ref: https://docs.mongodb.com/manual/reference/operator/update/each/

You can use mongodb method $push
db.users.update({"_id" : ObjectId("5d9fd81f3d598088d2ea5dcc")},
{ $push: {ancestors:ObjectId("5f45f9491ff4bd74ec754e3a") } })
[check doc][1]
[1]: https://docs.mongodb.com/manual/reference/operator/update/push/

Related

MongoDB get all embedded documents where condition is met

I did this in my mongodb:
db.teams.insert({name:"Alpha team",employees:[{name:"john"},{name:"david"}]});
db.teams.insert({name:"True team",employees:[{name:"oliver"},{name:"sam"}]});
db.teams.insert({name:"Blue team",employees:[{name:"jane"},{name:"raji"}]});
db.teams.find({"employees.name":/.*o.*/});
But what I got was:
{ "_id" : ObjectId("5ddf3ca83c182cc5354a15dd"), "name" : "Alpha team", "employees" : [ { "name" : "john" }, { "name" : "david" } ] }
{ "_id" : ObjectId("5ddf3ca93c182cc5354a15de"), "name" : "True team", "employees" : [ { "name" : "oliver" }, { "name" : "sam" } ] }
But what I really want is
[{"name":"john"},{"name":"oliver"}]
I'm having a hard time finding examples of this without using some kind of programmatic iterator/loop. Or examples I find return the parent document, which means I'd have to parse out the embedded array employees and do some kind of UNION statement?
Eg.
How to get embedded document in mongodb?
Retrieve only the queried element in an object array in MongoDB collection
Can someone point me in the right direction?
Please add projections to filter out the fields you don't need. Please refer the project link mongodb projections
Your find query should be constructed with the projection parameters like below:
db.teams.find({"employees.name":/.*o.*/}, {_id:0, "employees.name": 1});
This will return you:
[{"name":"john"},{"name":"oliver"}]
Can be solved with a simple aggregation pipeline.
db.teams.aggregate([
{$unwind : "$employees"},
{$match : {"employees.name":/.*o.*/}},
])
EDIT:
OP Wants to skip the parent fields. Modified query:
db.teams.aggregate([
{$unwind : "$employees"},
{$match : {"employees.name":/.*o.*/}},
{$project : {"name":"$employees.name",_id:0}}
])
Output:
{ "name" : "john" }
{ "name" : "oliver" }

MongoDB 4.0 aggregation addFields not saving documents after using toDate

I have the following documents,
{
"_id" : ObjectId("5b85312981c1634f59751604"),
"date" : "0"
},
{
"_id" : ObjectId("5b85312981c1634f59751604"),
"date" : "20180330"
},
{
"_id" : ObjectId("5b85312981c1634f59751604"),
"date" : "20180402"
},
{
"_id" : ObjectId("5b85312981c1634f59751604"),
"date" : "20180323"
},
I tried to convert date to ISODate using $toDate in aggregation,
db.documents.aggregate( [ { "$addFields": { "received_date": { "$cond": [ {"$ne": ["$date", "0"] }, {"$toDate": "$date"}, new Date("1970-01-01") ] } } } ] )
the query executed fine, but when I
db.documents.find({})
to examine all the documents, nothing changed, I am wondering how to fix it. I am using MongoDB 4.0.6 on Linux Mint 19.1 X64.
As they mentioned in the comments, aggregate doesn't update documents in the database directly (just an output of them).
If you'd like to permanently add a new field to documents via aggregation (aka update the documents in the database), use the following .forEach/.updateOne method:
Your example:
db.documents
.aggregate([{"$addFields":{"received_date":{"$cond":[{"$ne":["$date","0"]}, {"$toDate": "$date"}, new Date("1970-01-01")]}}}])
.forEach(function (x){db.documents.updateOne({_id: x._id}, {$set: {"received_date": x.received_date}})})
Since _id's value is an ObjectID(), there may be a slight modification you need to do to {_id:x._id}. If there is, let me know and I'll update it!
Another example:
db.users.find().pretty()
{ "_id" : ObjectId("5acb81b53306361018814849"), "name" : "A", "age" : 1 }
{ "_id" : ObjectId("5acb81b5330636101881484a"), "name" : "B", "age" : 2 }
{ "_id" : ObjectId("5acb81b5330636101881484b"), "name" : "C", "age" : 3 }
db.users
.aggregate([{$addFields:{totalAge:{$sum:"$age"}}}])
.forEach(function (x){db.users.updateOne({name: x.name}, {$set: {totalAge: x.totalAge}})})
Being able to update collections via the aggregation pipeline seems to be quite valuable because of what you have the power to do with aggregation (e.g. what you did in your question, doing calculations based on other fields within the document, etc.). I'm newer to MongoDB so maybe updating collections via aggregation pipeline is "bad practice", but it works and it's been quite valuable for me. I wonder why it isn't more straight-forward to do?
Note: I came up with this method after discovering Nazo's now-deprecated .save() method. Shoutout to Nazo!

mongodb extracting values from array

Following is example of table in mongodb, I have multiple records for companies like this, which I need help with.
I wanted to query the below table wherein using value from company I should be able to retrieve the name of all the cars.
"vehicles" : [
{
"source" : "jeep",
"tag" : [
{
"company" : "toyota",
"name" : "fortuner"
},
{
"company" : "rangerover",
"name" : "discovery"
]
}
]
Thanks...
try this :
db.vehicles.find({tag: {$elemMatch: {company:'toyota'}}}).pretty();
read more here : https://docs.mongodb.com/manual/reference/operator/query/elemMatch/

MongoDB update a subdocument attribute

Let me start by saying I'm sorry if this has been answered, but I can't get other questions on this site to fit my needs and, more importantly, work.
I have the below example document, with a subdocument of 'address':
{
"_id" : ObjectId("....")
,"addresses" :
[{
"start" : ISODate("1973-07-10T00:11:51.111Z")
,"value" : "123 long road"
}]
}
What I need to do is to close the existing address record with an end attribute, and add a new line for the new address with a new start and value attribute. Eventually, I'll need to do this again so the code needs to update the subdocument record where end does not exist.
The below code does not work, but it's about as far as I can get:
db.sites.update(
{"_id" : ObjectId("....")
, "addresses.end" : {"$exists" : false}}
,{"$set": {"addresses.$.end" : "fdsa"}});
This gives the error:
Cannot apply the positional operator without a corresponding query field containing an array.
Can anyone point me in the right direction?
Juste replace in your query "addresses.end" : {"$exists" : false} with:
addresses: {$elemMatch: {end: {$exists: false}}}
Your address field is poorly defined. you need make it a subdocument or an array of subdocuments. ie {
"_id" : ObjectId("....")
,"addresses" :
[
{
"start" : ISODate("1973-07-10T00:11:51.111Z")
,"value" : "123 long road"
}
]
}
your query should then work!
I think that the Query should be more specific
**Updated **
db.sites.update ( {"_id" : ObjectId("...."), addresses: { "$elemMatch" : { end:{$exists : false}} } }, {"$set": {"addresses.$.end" : "fdsa"}});
db.sites.find()
results:
{
"_id" : ObjectId("53df93da560b7815e1237934"),
"addresses" : [
{
"start" : ISODate("1973-07-10T00:11:51.111Z"),
"value" : "123 long road",
"end" : "fdsa"
}
]
}
but you can update only one
Take a look http://docs.mongodb.org/manual/reference/operator/projection/positional/#proj.S
You can t update more element in Array https://jira.mongodb.org/browse/SERVER-1243

Retrieving only the relevant part of a stored document

I'm a newbie with MongoDB, and am trying to store user activity performed on a site. My data is currently structured as:
{ "_id" : ObjectId("4decfb0fc7c6ff7ff77d615e"),
"activity" : [
{
"action" : "added",
"item_name" : "iPhone",
"item_id" : 6140,
},
{
"action" : "added",
"item_name" : "iPad",
"item_id" : 7220,
}
],
"name" : "Smith,
"user_id" : 2
}
If I want to retrieve, for example, all the activity concerning item_id 7220, I would use a query like:
db.find( { "activity.item_id" : 7220 } );
However, this seems to return the entire document, including the record for item 6140.
Can anyone suggest how this might be done correctly? I'm not sure if it's a problem with my query, or with the structure of the data itself.
Many thanks.
You have to wait the following dev: https://jira.mongodb.org/browse/SERVER-828
You can use $slice only if you know insertion order and position of your element.
Standard queries on MongoDb always return all document.
(question also available here: MongoDB query to return only embedded document)