In a find query projection, fields I specify after the positional operator are ignored and the whole document is always returned.
'myArray.$.myField' : 1 behave exactly like 'myArray.$' : 1
the positional operator selects the right document. But this document is quite big. I would like to project only 1 field from it.
Exemple:
db.getCollection('match').find({"participantsData.id" : 0001}, { 'participantsData.$.id': 1, })
here the response I have
{
"_id" : "myid",
"matchCreation" : 1463916465614,
"participantsData" : [
{
"id" : 0001,
"plenty" : "of",
"other" : "fields",
"and" : "subdocuments..."
}
]
}
This is what I want
{
"_id" : "myid",
"matchCreation" : 1463916465614,
"participantsData" : [
{
"id" : 0001
}
]
}
Is it possible with mongo?
Yes it can be done in mongo
Please try the below query
db.getCollection('match').find(
{"participantsData.id" : 0001},
{"participantsData.id": 1, "matchCreation": 1 })
This will give you the below result
{
"_id" : "myid",
"matchCreation" : 1463916465614,
"participantsData" : [
{
"id" : 1
}
]
}
Related
I need to be able to get a count of distinct 'transactions' the problem I'm having is that using .distinct() comes back with an error because the documents too large.
I'm not familiar with aggregation either.
I need to be able to group it by 'agencyID' as you see below there are 2 different agencyID's
I need to be able to count transactions where the agencyID is 01721487 etc
db.myCollection.distinct("bookings.transactions").length
this doesn't work as I need to be able to group by agencyID and if there are too many results I get an error saying it's too large.
{
"_id" : ObjectId("5624a610a6e6b53b158b4744"),
"agencyID" : "01721487",
"paxID" : "-530189664",
"bookings" : [
{
"bookingID" : "24232",
"transactions" : [
{
"tranID" : "001",
"invoices" : [
{
"invNum" : "1312",
"type" : "r",
"inv_date" : "20150723",
"inv_time" : "0953",
"inv_val" : -300
}
],
"tranType" : "Fee",
"tranDate" : "20150723",
"tranTime" : "0952",
"opCode" : "admin",
"udf_1" : "j s"
}
],
"acctID" : "acct11",
"agt_id" : "xy"
}
],
"title" : "",
"firstname" : "",
"surname" : "f bar"
}
I've also tried this but it didn't work for me.
thank you for text data -
this is something you could play with:
db.kieron.aggregate([{
$unwind : "$bookings"
}, {
$match : {
"bookings.transactions" : {
$exists : true,
$not : {
$size : 0
}
}
}
}, {
$group : {
_id : "$agencyID",
count : {
$sum : {
$size : "$bookings.transactions"
}
}
}
}
])
as there is nested array we need to unwind it first, and then we can check size of inner array.
Happy reporting!
I have collection with document structure :
{
'year' : 2014,
'month' : 1
}
I am executing the following operation :
db.collname.aggregate(
[
{
$project : {
'year100' : {$multiply : ["$year" , 100]},
'result' : { '$add' : ['$year100', '$month'] }
}
}
]
);
I get the following result :
{
"result" : [
{
"_id" : ObjectId("5563596c515a88832210f0e4"),
"year100" : 201400.0000000000000000,
"result" : null
},
}
Why is add operation returuning null value as against to actual value ? Please help.
MongoDb not allow to used same fields in project to arithmetic operation instead of one $project used two different projects like this :
db.collname.aggregate({ $project : { 'year100' : {$multiply : ["$year" , 100]} ,"month":"$month"} },{"$project":{"year100":1,"result":{"$add":["$year100","$month"]}}})
I have the following document structure
{
"_id" : "aaa0001",
"path" : "/some/path",
"information" : {
"name" : "info"
},
"colors" : {
"colors" : [
{
"key" : "AAAA001",
"name" : "White"
},
{
"key" : "BBBB002",
"name" : "Black"
}
]
}
}
the idea is that I have to return the document by the color key. I have two parameters the "path" and the "color", so, I was trying to make something like this
db.components.find(
{$and:[
{"path" : "/some/path"},
{"colors":{"colors" : {$elemMatch: { "key" : "AAAA001" } } } }
]})
I'm getting the following message "Script is executed successfully, but there is no results to show".
Can anyone give me some directions regarding this?
thanks
Use the following query:
db.components.find({
"path": "/some/path",
"colors.colors.key" : "AAAA001"
})
MongoDB expects query document to contain field-value pairs { <field>: <value> }. So, in your example you're querying for a document with colors field equal to:
{"colors" : {$elemMatch: { "key" : "AAAA001" } } }
As for $and and $elemMatch operators, you don't need them in such a simple query.
For more information read Query Documents.
Update
You can also select only matching subdocument from colors array using Positional Operator $:
db.components.find({
"path": "/some/path",
"colors.colors.key" : "AAAA001"
}, {
_id: 0,
"colors.colors.$": 1
})
Though, you won't be able to change your documents structure, thus getting
{ "colors" : { "colors" : [ { "key" : "AAAA001", "name" : "White" } ] } }
I have a collection with documents like this:
{
key : "bla"
list : [
{id:1},
{id:2}
]
}
How do I get this object: {id:1} ?
I tried a query like this: db.myCollection.find({"key":"bla", "list.id":1})
it finds the entry, but returns the complete document instead of only {id:1}
The $ operator is what you're looking for:
db.test.insert({key: "blah",list :[{id:1},{id:2}]})
db.test.find({'list.id' : 1},{'list.$': 1 })
#Returns:
#{ "_id" : ObjectId("521a78b342abf388fbaacf91"), "list" : [ { "id" : 1 } ] }
db.test.find({'list.id' : 2},{'list.$': 1 })
#Returns:
#{ "_id" : ObjectId("521a78b342abf388fbaacf91"), "list" : [ { "id" : 2 } ] }
If you don't need the _id of the document, you can exclude that too:
db.test.find({'list.id' : 2},{'list.$': 1 , _id: 0})
#Returns:
#{ "list" : [ { "id" : 2 } ] }
For more information, have a look at the documentation of the $ operator and read operations in general.
I am newbie in MongoDB. I have stored data inside mongoDB in below format
"_id" : ObjectId("51d5725c7be2c20819ac8a22"),
"chrom" : "chr22",
"pos" : 17060409,
"information" : [
{
"name" : "Category",
"value" : "3"
},
{
"name" : "INDEL",
"value" : "INDEL"
},
{
"name" : "DP",
"value" : "31"
},
{
"name" : "FORMAT",
"value" : "GT:PL:GQ"
},
{
"name" : "PV4",
"value" : "1,0.21,0.00096,1"
}
],
"sampleID" : "Job1373964150558382243283"
I want to update the value to 11 which has the name as Category.
I have tried below query:
db.VariantEntries.update({$and:[ { "pos" : 117199533} , { "sampleID" : "Job1373964150558382243283"},{"information.name":"Category"}]},{$set:{'information.value':'11'}})
but Mongo replies
can't append to array using string field name [value]
How one can form a query which will update the particular value?
You can use the $ positional operator to identify the first array element to match the query in the update like this:
db.VariantEntries.update({
"pos": 17060409,
"sampleID": "Job1373964150558382243283",
"information.name":"Category"
},{
$set:{'information.$.value':'11'}
})
In MongoDB you can't adress array values this way. So you should change your schema design to:
"information" : {
'category' : 3,
'INDEL' : INDEL
...
}
Then you can adress the single fields in your query:
db.VariantEntries.update(
{
{"pos" : 117199533} ,
{"sampleID" : "Job1373964150558382243283"},
{"information.category":3}
},
{
$set:{'information.category':'11'}
}
)