I have a collection with a location field that was entered in the wrong order:
location: [38.7633698, -121.2697997]
When I try to place a 2d index on the field using ...
db.collection.ensureIndex({'location': '2d'});
... I get the following error because the latitude and longitude are reversed.
"err" : "location object expected, location array not in correct format",
"code" : 13654
How can I reverse this array for each document in the mongo shell?
db.loc.find().forEach(function (doc) {
var loc = [ doc.location[1], doc.location[0] ];
db.loc.update(doc, { $set: { location: loc } });
})
Starting from MongoDB 3.4 we can use the $reverseArray operator to do this beautifully.
Reverse the array:
db.collection.aggregate(
[
{ "$project": { "location": { "$reverseArray": "$location" } } }
]
)
which yields:
{
"_id" : ObjectId("576fdc687d33ed2f37a6d527"),
"location" : [ -121.2697997, 38.7633698 ]
}
Update all documents
To update all the documents in your collection, you have a couple of options.
The first is to add a $out stage to your pipeline and replace the old collection. In this case, you will need to explicitly include all the other field in the $projection stage. The $out stage look like this:
{ "$out": "collection" }
Use $push
to reserve the array using the $each & $sort functionality of it
db.getCollection('locations').updateMany({},
{
$push: {
'geo_point.coordinates': { $each: [ ], $sort: -1 }
}
});
Related
I have a MongoDB collection of documents formatted as shown below:
{
"_id" : ...,
"username" : "foo",
"challengeDetails" : [
{
"ID" : ...,
"pb" : 30081,
},
{
"ID" : ...,
"pb" : 23995,
},
...
]
}
How can I write a find query for records that have a challengeDetails documents with a matching ID and sort them by the corresponding PB?
I have tried (this is using the NodeJS driver, which is why the projection syntax is weird)
const result = await collection
.find(
{ "challengeDetails.ID": challengeObjectID},
{
projection: {"challengeDetails.$": 1},
sort: {"challengeDetails.0.pb": 1}
}
)
This returns the correct records (documents with challengeDetails for only the matching ID) but they're not sorted.
I think this doesn't work because as the docs say:
When the find() method includes a sort(), the find() method applies the sort() to order the matching documents before it applies the positional $ projection operator.
But they don't explain how to sort after projecting. How would I write a query to do this? (I have a feeling aggregation may be required but am not familiar enough with MongoDB to write that myself)
You need to use aggregation to sort n array
$unwind to deconstruct the array
$match to match the value
$sort for sorting
$group to reconstruct the array
Here is the code
db.collection.aggregate([
{ "$unwind": "$challengeDetails" },
{ "$match": { "challengeDetails.ID": 2 } },
{ "$sort": { "challengeDetails.pb": 1 } },
{
"$group": {
"_id": "$_id",
"username": { "$first": "$username" },
"challengeDetails": { $push: "$challengeDetails" }
}
}
])
Working Mongo playground
I am trying to update the property name of the json in mongodb document.
{
"_id" : ObjectId("1234556789"),
"apps" : [
{
"_id" : 101,
"regions" : [
"WANAE",
"WANAF"
]
},
{
"_id" : 102,
"regions" : [
"WANAE",
"WANAF"
]
}
]
}
in the above josn, I want to change apps regions to codes. Treid below queries but did not work
db.packs.updateMany( {}, { $rename: { 'apps.$.regions': 'apps.$.codes' } } );
db.packs.updateMany( {}, { $rename: { 'apps.$[].regions': 'apps.$[].codes' } } );
any help
Update: As Joe suggested, I have a aggregation that changes the document with the changes needed and I tried updating the entire collection like below with the aggregated result
db.packs.aggregate([
{
$addFields: {
apps: {
$map: {
input: "$apps",
as: "app",
in: {
_id: "$$app._id",
did: "$$app.did",
name: "$$app.name",
codes: "$$app.regions"
}
}
}
}
},
{
$project:{
"apps.regions":0
}
},
{
$out:"packs"
}
])
As per the documentation, $out should replace the existing collection if it is exists but I received an error that says I have to supply a new collection name Please supply a collection that does not already exist to the $out stage.. Isn't $Out replace the exiting packs with new aggregated results
When you reference a field in an array of objects, like "$apps.regions", the value is an array containing all of the values of that field from all of the elements.
If you set the value of regions directly, each sub document will contain an array of arrays, probably not what you want.
renaming the field in the entire array of objects will require iterating the array, perhaps with $map or $reduce.
If you are using MongoDB 4.2, you can do that with a pipeline in an update:
db.packs.updateMany( {}, [
{$set: {
"apps": {
$map: {
input: "$apps",
in: {
$mergeObjects: [
"$$this",
{
codes: "$$this.regions"
}
]
}
}
}
}},
{$unset: "apps.regions"}
]}
If you are using an earlier version, you'll need to do that with aggregation, perhaps with $out, and then replace the original collection with the updated one.
Mongo does not allow documents to have dots in their keys (see MongoDB dot (.) in key name or https://softwareengineering.stackexchange.com/questions/286922/inserting-json-document-with-in-key-to-mongodb ).
However we have a huge mongo database where some documents do contain dots in their keys. These documents are of the form:
{
"_id" : NumberLong(2761632),
"data" : {
"field.with.dots" : { ... }
}
}
I don't know how these records got inserted. I suspect that we must have had the check_keys mongod option set to false at some point.
My goal is to find the offending documents, to update them and remove the dots. I haven't found how to perform the search query. Here is what I tried so far:
db.collection.find({"data.field.with.dots" : { $exists : true }})
db.collection.find({"data.field\uff0ewith\uff0edots" : { $exists : true}})
You can use $objectToArray to get your data in form of keys and values. Then you can use $filter with $indexOfBytes to check if there are any keys with . inside of it . In the next step you can use $size to filter out those documents where remaining array is empty (no fields with dots), try:
db.col.aggregate([
{
$addFields: {
dataKv: {
$filter: {
input: { $objectToArray: "$data" },
cond: {
$ne: [ { $indexOfBytes: [ "$$this.k", "." ] } , -1 ]
}
}
}
}
},
{
$match: {
$expr: {
$ne: [ { $size: "$dataKv" }, 0 ]
}
}
},
{
$project: {
dataKv: 0
}
}
])
Mongo playground
I have a document in the following form:
{
"_id" : <id of document>,
"inventory" : [
{
"entity_id" : "<id>",
"ad_type" : "ADTYPE"
}
]
}
I'm not sure if this is possible in mongo but I am trying to construct an upsert query on the above document where I will insert an empty array if inventory doesn't exist or push to the array if inventory has one or more elements.
I tried using the findAndModify function but I don't think that will work.
db.collection.find({"_id":"value"}).forEach(
function(doc){
if(doc.hasOwnProperty('inventory'))
{
db.collection.update({"_id":doc._id},
{"$push":{"inventory": "new value"}});
}
else
{
db.collection.update({"_id":doc._id},
{"$set":{"inventory": new Array() }});
}
});
"collection" is array, "subcollection" is object.
The script adds new field "rank" to array element with index 1.
If the field doesn't exist the script creates "rank" and set value, If the field exists the script update value.
db.userCollection.update(
{ "_id": ObjectId("5a1e7aefd1928362e53c5c48"),
$and: [ { "collection.1.subcollection.id": "1234" },
{ "collection.1.rank": {"$ne": -1 }}
]
},
{ $set: { "collection.1.rank": "5" }
}
)
How do I concatenate values from two string fields and put it into a third one?
I've tried this:
db.collection.update(
{ "_id": { $exists: true } },
{ $set: { column_2: { $add: ['$column_4', '$column_3'] } } },
false, true
)
which doesn't seem to work though, and throws not ok for storage.
I've also tried this:
db.collection.update(
{ "_id": { $exists : true } },
{ $set: { column_2: { $add: ['a', 'b'] } } },
false, true
)
but even this shows the same error not ok for storage.
I want to concatenate only on the mongo server and not in my application.
You can use aggregation operators $project and $concat:
db.collection.aggregate([
{ $project: { newfield: { $concat: [ "$field1", " - ", "$field2" ] } } }
])
Unfortunately, MongoDB currently does not allow you to reference the existing value of any field when performing an update(). There is an existing Jira ticket to add this functionality: see SERVER-1765 for details.
At present, you must do an initial query in order to determine the existing values, and do the string manipulation in the client. I wish I had a better answer for you.
You could use $set like this in 4.2 which supports aggregation pipeline in update.
db.collection.update(
{"_id" :{"$exists":true}},
[{"$set":{"column_2":{"$concat":["$column_4","$column_3"]}}}]
)
Building on the answer from #rebe100x, as suggested by #Jamby ...
You can use $project, $concat and $out (or $merge) in an aggregation pipeline.
https://docs.mongodb.org/v3.0/reference/operator/aggregation/project/
https://docs.mongodb.org/manual/reference/operator/aggregation/concat/
https://docs.mongodb.com/manual/reference/operator/aggregation/out/
For example:
db.collection.aggregate(
[
{ $project: { newfield: { $concat: [ "$field1", " - ", "$field2" ] } } },
{ $out: "collection" }
]
)
With MongoDB 4.2 . . .
MongoDB 4.2 adds the $merge pipeline stage which offers selective replacement of documents within the collection, while $out would replace the entire collection. You also have the option of merging instead of replacing the target document.
db.collection.aggregate(
[
{ $project: { newfield: { $concat: [ "$field1", " - ", "$field2" ] } } },
{ $merge: { into: "collection", on: "_id", whenMatched: "merge", whenNotMatched: "discard" }
]
)
You should consider the trade-offs between performance, concurrency and consistency, when choosing between $merge and $out, since $out will atomically perform the collection replacement via a temporary collection and renaming.
https://docs.mongodb.com/manual/reference/operator/aggregation/merge/
https://docs.mongodb.com/manual/reference/operator/aggregation/merge/#merge-out-comparison
**
in my case this $concat worked for me ...
**
db.collection.update( { "_id" : {"$exists":true} },
[ {
"$set" : {
"column_2" : { "$concat" : ["$column_4","$column_3"] }
}
}
]
let suppose that you have a collection name is "myData" where you have data like this
{
"_id":"xvradt5gtg",
"first_name":"nizam",
"last_name":"khan",
"address":"H-148, Near Hero Show Room, Shahjahanpur",
}
and you want concatenate fields (first_name+ last_name +address) and save it into "address" field like this
{
"_id":"xvradt5gtg",
"first_name":"nizam",
"last_name":"khan",
"address":"nizam khan,H-148, Near Hero Show Room, Shahjahanpur",
}
now write query will be
{
var x=db.myData.find({_id:"xvradt5gtg"});
x.forEach(function(d)
{
var first_name=d.first_name;
var last_name=d.last_name;
var _add=d.address;
var fullAddress=first_name+","+last_name+","+_add;
//you can print also
print(fullAddress);
//update
db.myData.update({_id:d._id},{$set:{address:fullAddress}});
})
}
You can also follow the below.
db.collectionName.find({}).forEach(function(row) {
row.newField = row.field1 + "-" + row.field2
db.collectionName.save(row);
});
Find and Update Each Using For Loop
Try This:
db.getCollection('users').find({ }).forEach( function(user) {
user.full_name = user.first_name + " " + user.last_name;
db.getCollection('users').save(user);
});
Or Try This:
db.getCollection('users').find({ }).forEach( function(user) {
db.getCollection('users').update(
{ _id: user._id },
{ $set: { "full_name": user.first_name + " " + user.last_name } }
)
});