I am trying to return events where someone has not been invited to. However,
all my queries are returning data. Nothing should be returned when I run the query. What am I missing?
"__v" : 0,
"_id" : ObjectId("565cca79a9baa9b1522b57eb"),
"attendees" : [
{
"_id" : ObjectId("565cca79a9baa9b1522b57ec"),
"attendee" : ObjectId("557dfb4fc8c9ecbb07c2f98c"),
"statustext" : "Accepted",
"status" : 1
},
{
"attendee" : ObjectId("55dec11f38180102145d0060"),
"_id" : ObjectId("565f6bacdcbac0a6a354420c"),
"statustext" : "Pending",
"status" : 0
}
]
db.events.find({attendees:{$elemMatch:{attendee:{$ne:"55dec11f38180102145d0060"}}}}).
db.events.find({attendees:{$elemMatch:{attendee:{$ne:'55dec11f38180102145d0060'}}}})
db.events.find({attendees:{$elemMatch:{attendee:{$ne:ObjectId('55dec11f38180102145d0060')}}}})
Quoting the docs:
The $elemMatch operator matches documents that contain an array field
with at least one element that matches all the specified query
criteria.
That means the $elemMatch is not suited for this case.
db.events.find({"attendees.attendee":{$ne: ObjectId("55dec11f38180102145d0060")}})
Related
I have documents like this in a collection called 'variants':
{
"_id" : "An_FM000900_Var_10_100042505_100042505_G_A",
"analysisId" : "FM000900",
"chromosome" : 10,
"start" : 100042505,
"end" : 100042505,
"size" : 1,
"reference" : "G",
"alternative" : "A",
"effects" : [
{
"_id" : "Analysis:FM000900-Variant:An_FM000900_Var_10_100042505_100042505_G_A-Effect:0",
"biotype" : "protein_coding",
"impact" : "LOW",
},
{
"_id" : "Analysis:FM000900-Variant:An_FM000900_Var_10_100042505_100042505_G_A-Effect:1",
"biotype" : "protein_coding",
"impact" : "MODERATE",
}
]
}
I want to find documents in that collection that meet some criteria ("analysisId":"FM000900"), and after that I want to project over 'effects' array field to bring just the first element in 'effects' array that meet some criteria ("biotype" : "protein_coding" and "impact" : "MODERATE").
The thing is that I just want to show the main 'variant' document if and only if at least one element in the 'effects' array has meet the criteria.
With the following query I get the expected result except that I get 'variant' documents with 'effects' array field empty.
db.getCollection('variants').find(
{
"analysisId":"FM000900"
}
,
{
"effects":{
"$elemMatch" : {
"biotype" : "protein_coding",
"impact" : "MODERATE"
}
}
}
).skip(0).limit(200)
Can somebody transform this query to only get 'variant' documents with some element in 'effect' array after the projection if possible?
Can it be done in another way, without using aggregation framework if possible? as the collection has millions of documents and it has to be performant.
Thanks a lot, guys!!!
Simply use $elemMatch as query operator in addition of your projection, it will filter variants that have at least one effects array element that match all conditions.
So your query will be :
db.getCollection('variants').find(
{
"analysisId":"FM000900",
"effects":{
"$elemMatch" : {
"biotype" : "protein_coding",
"impact" : "MODERATE"
}
}
}
,
{
"effects":{
"$elemMatch" : {
"biotype" : "protein_coding",
"impact" : "MODERATE"
}
}
}
).skip(0).limit(200)
In addition, a compound multikey index that covers both query and projection can improve reading performance, but use it carefully as it can drastically reduce writing performances.
Have records in my db with such structure:
{
"_id" : "YA14163134",
"discount" : "",
"retail" : "115.0000",
"cost" : "",
"description" : "Caterpillar Mens Big Twist Analog Watch",
"stock_update" : "05",
"brand" : "Kronos",
"img_url" : "image2342000.jpg",
"UPC" : "4895053708012",
"stock" : [ [ "1611292138", "5" ], [ "1612032232", "4" ], [ "1612050918", "0" ] ]
}
and looking for query to get all records that have in "stock" "1612050918" value. That is update id.
Trying something like:
db.vlc.find({stock: {$elemMatch:{$all:["1612050918"]}}})
or
db.vlc.find({stock: { $in : ['1611292138']}})
or
db.vlc.find({stock: { $all : [[1611292138]]}})
with no result. It works only if I include in request second array element like here
db.vlc.find({stock: { $all : [['1611292138', '7']]}})
but that limit my request to all items from update with qnty 7 when I need with any qnty. Thank you in advance!
use this query:
{
"stock" : {
"$elemMatch" : {
"$elemMatch" : {
"$eq" : "1611292138"
}
}
}
}
Explanation:
The first $elemMatch allows you to scan all three arrays under stock
The nex $elemMatch allows you to scan the two elements in the sub-arrays
since $elemMatch requires a query object, the $eq notation is used for a literal match.
If you know that "1611292138" will always be the first element of the sub-array, your query becomes simpler:
{ "stock" : { "$elemMatch" : { "0" : "1611292138" } } }
Explanation:
Scan all arrays under stock
Look for "1611292138" in the first slot of each sub-array
Use nested $elemMatch as below :
db.vlc.find({stock: { "$elemMatch":{"$elemMatch":{"$all":["1612050918"]}}}})
Or
db.vlc.find({stock: {"$elemMatch":{ "$elemMatch":{"$in" : ["1612050918"]}}}})
I have a mongo document which has structure like
{
"_id" : "THIS_IS_A_DHP_USER_ID+2014-11-26",
"_class" : "weight",
"items" : [
{
"dateTime" : ISODate("2014-11-26T08:08:38.716Z"),
"value" : 98.5
},
{
"dateTime" : ISODate("2014-11-26T08:18:38.716Z"),
"value" : 95.5
},
{
"dateTime" : ISODate("2014-11-26T08:28:38.663Z"),
"value" : 90.5
}
],
"source" : "MANUAL",
"to" : ISODate("2014-11-26T08:08:38.716Z"),
"from" : ISODate("2014-11-26T08:08:38.716Z"),
"userId" : "THIS_IS_A_DHP_USER_ID",
"createdDate" : ISODate("2014-11-26T08:38:38.776Z")
}
{
"_id" : "THIS_IS_A_DHP_USER_ID+2014-11-25",
"_class" : "weight",
"items" : [
{
"dateTime" : ISODate("2014-11-25T08:08:38.716Z"),
"value" : 198.5
},
{
"dateTime" : ISODate("2014-11-25T08:18:38.716Z"),
"value" : 195.5
},
{
"dateTime" : ISODate("2014-11-25T08:28:38.716Z"),
"value" : 190.5
}
],
"source" : "MANUAL",
"to" : ISODate("2014-11-25T08:08:38.716Z"),
"from" : ISODate("2014-11-25T08:08:38.716Z"),
"userId" : "THIS_IS_A_DHP_USER_ID",
"createdDate" : ISODate("2014-11-26T08:38:38.893Z")
}
The query that want to fire on this document structure,
finding documents for a particular user id
unwinding the embedded array
Grouping the documents based over _id with -
summing the items.value of the embedded array
getting the minimum of the items.dateTime of the embedded array
Note. The sum and min, I want to get as a object i.e. { value : sum , dateTime : min of the items.dateTime} inside an array of items
Can this be achieved in an single aggregation call using push or some other technique.
When you group over a particular _id, and apply aggregation operators such as $min and $sum, there exists only one record per group(_id), that holds the sum and the minimum date for that group. So there is no way to obtain a different sum and a different minimum date for the same _id, which also logically makes no sense.
What you would want to do is:
db.collection.aggregate([
{$match:{"userId":"THIS_IS_A_DHP_USER_ID"}},
{$unwind:"$items"},
{$group:{"_id":"$_id",
"values":{$sum:"$items.value"},
"dateTime":{$min:"$items.dateTime"}}}
])
But in case when you do not query for a particular userId, then you would have multiple groups, each group having its own sum and min date. Then it makes sense to accumulate all these results together in an array using the $push operator.
db.collection.aggregate([
{$unwind:"$items"},
{$group:{"_id":"$_id",
"result":{$sum:"$items.value"},
"dateTime":{$min:"$items.dateTime"}}},
{$group:{"_id":null,"result":{$push:{"value":"$result",
"dateTime":"$dateTime",
"id":"$_id"}}}},
{$project:{"_id":0,"result":1}}
])
you should use following aggregation may it works
db.collectionName.aggregate(
{"$unwind":"$items"},
{"$match":{"userId":"THIS_IS_A_DHP_USER_ID"}},
{"$group":{"_id":"$_id","sum":{"$sum":"$items.value"},
"minDate":{"$min":"$items.dateTime"}}}
)
I need get a specific object in array of array in MongoDB.
I need get only the task object = [_id = ObjectId("543429a2cb38b1d83c3ff2c2")].
My document (projects):
{
"_id" : ObjectId("543428c2cb38b1d83c3ff2bd"),
"name" : "new project",
"author" : ObjectId("5424ac37eb0ea85d4c921f8b"),
"members" : [
ObjectId("5424ac37eb0ea85d4c921f8b")
],
"US" : [
{
"_id" : ObjectId("5434297fcb38b1d83c3ff2c0"),
"name" : "Test Story",
"author" : ObjectId("5424ac37eb0ea85d4c921f8b"),
"tasks" : [
{
"_id" : ObjectId("54342987cb38b1d83c3ff2c1"),
"name" : "teste3",
"author" : ObjectId("5424ac37eb0ea85d4c921f8b")
},
{
"_id" : ObjectId("543429a2cb38b1d83c3ff2c2"),
"name" : "jklasdfa_XXX",
"author" : ObjectId("5424ac37eb0ea85d4c921f8b")
}
]
}
]
}
Result expected:
{
"_id" : ObjectId("543429a2cb38b1d83c3ff2c2"),
"name" : "jklasdfa_XXX",
"author" : ObjectId("5424ac37eb0ea85d4c921f8b")
}
But i not getting it.
I still testing with no success:
db.projects.find({
"US.tasks._id" : ObjectId("543429a2cb38b1d83c3ff2c2")
}, { "US.tasks.$" : 1 })
I tryed with $elemMatch too, but return nothing.
db.projects.find({
"US" : {
"tasks" : {
$elemMatch : {
"_id" : ObjectId("543429a2cb38b1d83c3ff2c2")
}
}
}
})
Can i get ONLY my result expected using find()? If not, what and how use?
Thanks!
You will need an aggregation for that:
db.projects.aggregate([{$unwind:"$US"},
{$unwind:"$US.tasks"},
{$match:{"US.tasks._id":ObjectId("543429a2cb38b1d83c3ff2c2")}},
{$project:{_id:0,"task":"$US.tasks"}}])
should return
{ task : {
"_id" : ObjectId("543429a2cb38b1d83c3ff2c2"),
"name" : "jklasdfa_XXX",
"author" : ObjectId("5424ac37eb0ea85d4c921f8b")
}
Explanation:
$unwind creates a new (virtual) document for each array element
$match is the query part of your find
$project is similar as to project part in find i.e. it specifies the fields you want to get in the results
You might want to add a second $match before the $unwind if you know the document you are searching (look at performance metrics).
Edit: added a second $unwind since US is an array.
Don't know what you are doing (so realy can't tell and just sugesting) but you might want to examine if your schema (and mongodb) is ideal for your task because the document looks just like denormalized relational data probably a relational database would be better for you.
I have the folowing Mongo db schema :
"Price_History" : [
{
"pr" : 62,
"BookingDateTo" : "2014-08-05T18:41:35",
"CollectionDate" : "2014-07-22T18:41:35",
"Vendor" : "test",
"BookingDateFrom" : "2014-08-04T18:41:35"
},
{
"BookingDateFrom" : "2014-08-04T23:01:37",
"BookingDateTo" : "2014-08-05T23:01:37",
"pr" : 62,
"Vendor" : "test",
"CollectionDate" : "2014-07-19T23:01:37"
}
],
this should be:
"Price_History" : [
{
"pr" : 62,
"BookingDateTo" : "2014-08-05T18:41:35",
"CollectionDate" : "2014-07-22T18:41:35",
"Vendor" : "Trv",
"BookingDateFrom" : "2014-08-04T18:41:35"
},
The query should delete multiple items in an array if Price_History.CollectionDate is older then 2014-07-19T23:01:37
Finally the query should update all documents
is that posible ?
You're close, but you've got some mis-matched quotes in your keys which is breaking things and it should be:
db.coll.update({},
{$pull: {Price_History: {CollectionDate: {$lte : "2014-07-19T23:01:37"}}}},
{multi: true})
I also changed it to use $lte since you were looking for "older than". Using $pull instead of $pullAll is also important here as $pullAll only removes elements that match exactly while $pull performs a query match.