Develop Reference

How do I get the value from the ArrayOfObjects dynamically in MongoDB document with Java driver

I have got a below document in Mongodb collection , need to get the value of result of false with Java syntax .Any help can be appreciated .
{
"_id" : ObjectId("5f0890e870e631865877e"),
"user" : "testuser",
"Email" : "testuser#sample.com",
"Batch Systems" : [
"STAR",
"STORY",
"ITEMS",
],
"Email Systems" : [
{
"Bob" : {
"System" : "Bob",
**"result"** : true
}
},
{
"Wild" : {
"System" : "Wild",
"result" : true
}
}
{
"CRaft" : {
"System" : "Craft",
"result" : false
}
}
],
I can't go like Email Systems.Bob.result ,Email Systems.Wild.result,Email Systems.Craft.result .Can anyone suggest how to get the result value from all systems with Java synatax.

MongoDB Search nested Objects without knowing Key

I have a list of objects that are given somewhat arbitrary Object keys as a result of using the async Java driver + BSON.
My issue is given the fact that jobStatuses are an arbitrary list of Dictionary items where I don't know the key, I have no idea how to access its sub-values. In the end, I'm trying to build a query that returns if ANY of jobStatus.*._id are true given a list of potential Object ID's.
So I'd be giving a list of ID's and want to return true if ANY of the items in jobStatuses have any of the given ID's. Any ideas?

Let's try this :
db.yourCollectionName.aggregate([
{
$project: {
_id: 0,
jobStatutses: { $arrayElemAt: [{ $objectToArray: "$jobStatutses" }, 0] }
}
}, {
$match: { 'jobStatutses.v._id': { $in: [ObjectId("5d6d8c3a5a0d22d3c84dd6dc"), ObjectId("5d6d8c3a5a0d22d3c84dd6ed")] } }
}
])
Collection Data :
/* 1 */
{
"_id" : ObjectId("5e06319c400289966eea6a07"),
"jobStatutses" : {
"5d6d8c3a5a0d22d3c84dd6dc" : {
"_id" : ObjectId("5d6d8c3a5a0d22d3c84dd6dc"),
"accepted" : "123",
"completed" : 0
}
},
"something" : 1
}
/* 2 */
{
"_id" : ObjectId("5e0631ad400289966eea6dd1"),
"jobStatutses" : {
"5d6d8c3a5a0d22d3c84dd6ed" : {
"_id" : ObjectId("5d6d8c3a5a0d22d3c84dd6ed"),
"accepted" : "456",
"completed" : 0
}
},
"something" : 2
}
/* 3 */
{
"_id" : ObjectId("5e0631cd400289966eea7542"),
"jobStatutses" : {
"5e06319c400289966eea6a07" : {
"_id" : ObjectId("5e06319c400289966eea6a07"),
"accepted" : "789",
"completed" : 0
}
},
"something" : 3
}
Output :
/* 1 */
{
"jobStatutses" : {
"k" : "5d6d8c3a5a0d22d3c84dd6dc",
"v" : {
"_id" : ObjectId("5d6d8c3a5a0d22d3c84dd6dc"),
"accepted" : "123",
"completed" : 0
}
}
}
/* 2 */
{
"jobStatutses" : {
"k" : "5d6d8c3a5a0d22d3c84dd6ed",
"v" : {
"_id" : ObjectId("5d6d8c3a5a0d22d3c84dd6ed"),
"accepted" : "456",
"completed" : 0
}
}
}
All you need is to check if at least one doc gets returned from DB for a given list or not, So we don't need to worry about document structure then just do result.length in your code to say at least one doc got matched for the input list.

Why I'm getting documents not included in the projection?

I have these 2 documents in my collection:
{
"_id" : ObjectId("5722042f8648ba1d04c65dad"),
"companyId" : ObjectId("570269639caabe24e4e4043e"),
"applicationId" : ObjectId("5710e3994df37620e84808a8"),
"steps" : [
{
"id" : NumberLong(0),
"responsiveUser" : "57206f9362d0260fd0af59b6",
"stepOnRejection" : NumberLong(0),
"notification" : "test"
},
{
"id" : NumberLong(1),
"responsiveUser" : "57206fd562d0261034075f70",
"stepOnRejection" : NumberLong(1),
"notification" : "test1"
}
]
}
{
"_id" : ObjectId("5728f317a8f9ba14187b84f8"),
"companyId" : ObjectId("570269639caabe24e4e4043e"),
"applicationId" : ObjectId("5710e3994df37620e84808a8"),
"steps" : [
{
"id" : NumberLong(0),
"responsiveUser" : "57206f9362d0260fd0af59b6",
"stepOnRejection" : NumberLong(0),
"notification" : "erter"
},
{
"id" : NumberLong(1),
"responsiveUser" : "57206f9362d0260fd0af59b6",
"stepOnRejection" : NumberLong(1),
"notification" : "3232"
}
]
}
Now I'm trying to get the document with the max _id and the id that equals 0 from a document inside of the steps array. I also have a projection that is supposed to show only the id of the matched element and nothing else.
Here is my query:
collection
.find(new Document("companyId", companyId)
.append("applicationId", applicationId)
.append("steps",
new Document("$elemMatch",
new Document("id", 0))))
.sort(new Document("_id", 1))
.limit(1)
.projection(new Document("steps.id", 1)
.append("_id", 0));
And it returns:
Document{{steps=[Document{{id=0}}, Document{{id=1}}]}}
Why is it returning 2 documents instead of 1?
The result should be looking like:
Document{{id=0}}
What am I missing here? I know that is something basic, but I really can't spot my mistake here.

Your query document tells Mongo to return those documents where in the 'steps' array they have a document where id: 0. You are NOT telling Mongo to return ONLY that field. You can use $elemMatch inside the projection document to get what you want (I'm writing this in the Mongo shell syntax because I'm not too familiar with the Java syntax):
{ steps: { $elemMatch: { id: 0 } },
'steps.id': 1,
_id: 0
}

Error in Creating JSON object

I'm getting an JSON array as a string value and I need to create a JSON object using that. array code is like this.
{"eventsList" : [
"requestId" : "82334-adf86d-8bac8ef-289c"
events:[
{
"eventType" : "receiveLocation_Event",
"externalId" : "973af2f8-820b-457b-89c2",
"description" : "Test Event",
"whenOccurred" : "06-Aug-2013 07.15.01.0 AM",
"partnerId" : "cecdbd94-ac60-4db0-b7f2",
"tagsAndValues" : {
"locationAccuracy" : "10",
"attr2" : "value2"
},
"count" : "2"
},
{
"eventType" : "SEND_SMS_sendSmsEvent",
"externalId" : "45af4f8-87-4f42b-832abc",
"description" : "Another Test Event",
"whenOccurred" : "06-Aug-2013 08.16.01.0 AM",
"partnerId" : "cecdbd94-ac60-4db0-b7f2",
"tagsAndValues" : {
"messageLength" : "135",
"attrX" : "valueX"
},
"count" : "1"
}
]
}
]
}
i try to create an JSON object using folowing code line
SONObject jsonObject = new JSONObject(string);
I'm getting an error when i run this.
org.json.JSONException: Expected a ',' or ']' at character 35
at org.json.JSONTokener.syntaxError(JSONTokener.java:413)
at org.json.JSONArray.<init>(JSONArray.java:143)
at org.json.JSONTokener.nextValue(JSONTokener.java:351)
at org.json.JSONObject.<init>(JSONObject.java:206)
at org.json.JSONObject.<init>(JSONObject.java:420)
Please help me to solve this issue.

There are several mistakes.
After [ a list of comma-separated values is expected, but you have a colon after "requestId". You probably meant for the [ on line 1 to be a {.
Given the last issue, you probably want a comma after "82334-adf86d-8bac8ef-289c"
If you drop your text into an online JSON formatter and validator, such as this one it will point out all your errors.

Problem is here:
...
"requestId" : "82334-adf86d-8bac8ef-289c"
events:...
You forgot some punctuation:
...
"requestId" : "82334-adf86d-8bac8ef-289c",
"events":......
Use this instead this is JSON syntax. All keys are strings.

This is how the String should be;
{"eventsList" : [
{"requestId" : "82334-adf86d-8bac8ef-289c"},
{ "events":[
{
"eventType" : "receiveLocation_Event",
"externalId" : "973af2f8-820b-457b-89c2",
"description" : "Test Event",
"whenOccurred" : "06-Aug-2013 07.15.01.0 AM",
"partnerId" : "cecdbd94-ac60-4db0-b7f2",
"tagsAndValues" : {
"locationAccuracy" : "10",
"attr2" : "value2"
},
"count" : "2"
},
{
"eventType" : "SEND_SMS_sendSmsEvent",
"externalId" : "45af4f8-87-4f42b-832abc",
"description" : "Another Test Event",
"whenOccurred" : "06-Aug-2013 08.16.01.0 AM",
"partnerId" : "cecdbd94-ac60-4db0-b7f2",
"tagsAndValues" : {
"messageLength" : "135",
"attrX" : "valueX"
},
"count" : "1"
}
]
}
]
}
the requestId and event must be like this: {"requestId" : "82334-adf86d-8bac8ef-289c"},
{ "events":
And also there must be closing } after closing the inner JSONArray ]

Gets documents and total count of them in single query include pagination

I'm new in mongo and use mongodb aggregation framework for my queries. I need to retrieve some records which satisfy certain conditions(include pagination+sorting) and also get total count of records.
Now, I perform next steps:
Create $match operator
{ "$match" : { "year" : "2012" , "author.authorName" : { "$regex" :
"au" , "$options" : "i"}}}
Added sorting and pagination
{ "$sort" : { "some_field" : -1}} , { "$limit" : 10} , { "$skip" : 0}
After querying I receive the expected result: 10 documents with all fields.
For pagination I need to know the total count of records which satisfy these conditions, in my case 25.
I use next query to get count : { "$match" : { "year" : "2012" , "author.authorName" : { "$regex" : "au" , "$options" : "i"}}} , { "$group" : { "_id" : "$all" , "reviewsCount" : { "$sum" : 1}}} , { "$sort" : { "some_field" : -1}} , { "$limit" : 10} , { "$skip" : 0}
But I don't want to perform two separate queries: one for retrieving documents and second for total counts of records which satisfy certain conditions.
I want do it in one single query and get result in next format:
{
"result" : [
{
"my_documets": [
{
"_id" : ObjectId("512f1f47a411dc06281d98c0"),
"author" : {
"authorName" : "author name1",
"email" : "email1#email.com"
}
},
{
"_id" : ObjectId("512f1f47a411dc06281d98c0"),
"author" : {
"authorName" : "author name2",
"email" : "email2#email.com"
}
}, .......
],
"total" : 25
}
],
"ok" : 1
}
I tried modify the group operator : { "$group" : { "_id" : "$all" , "author" : "$author" "reviewsCount" : { "$sum" : 1}}}
But in this case I got : "exception: the group aggregate field 'author' must be defined as an expression inside an object". If add all fields in _id then reviewsCount always = 1 because all records are different.
Nobody know how it can be implement in single query ? Maybe mongodb has some features or operators for this case? Implementation with using two separate query reduces performance for querying thousand or millions records. In my application it's very critical performance issue.
I've been working on this all day and haven't been able to find a solution, so thought i'd turn to the stackoverflow community.
Thanks.

You can try using $facet in the aggregation pipeline as
db.name.aggregate([
{$match:{your match criteria}},
{$facet: {
data: [{$sort: sort},{$skip:skip},{$limit: limit}],
count:[{$group: {_id: null, count: {$sum: 1}}}]
}}
])
In data, you'll get your list with pagination and in the count, count variable will have a total count of matched documents.

Ok, I have one example, but I think it's really crazy query, I put it only for fun, but if this example faster than 2 query, tell us about it in the comments please.
For this question i create collection called "so", and put into this collection 25 documents like this:
{
"_id" : ObjectId("512fa86cd99d0adda2a744cd"),
"authorName" : "author name1",
"email" : "email1#email.com",
"c" : 1
}
My query use aggregation framework:
db.so.aggregate([
{ $group:
{
_id: 1,
collection: { $push : { "_id": "$_id", "authorName": "$authorName", "email": "$email", "c": "$c" } },
count: { $sum: 1 }
}
},
{ $unwind:
"$collection"
},
{ $project:
{ "_id": "$collection._id", "authorName": "$collection.authorName", "email": "$collection.email", "c": "$collection.c", "count": "$count" }
},
{ $match:
{ c: { $lte: 10 } }
},
{ $sort :
{ c: -1 }
},
{ $skip:
2
},
{ $limit:
3
},
{ $group:
{
_id: "$count",
my_documets: {
$push: {"_id": "$_id", "authorName":"$authorName", "email":"$email", "c":"$c" }
}
}
},
{ $project:
{ "_id": 0, "my_documets": "$my_documets", "total": "$_id" }
}
])
Result for this query:
{
"result" : [
{
"my_documets" : [
{
"_id" : ObjectId("512fa900d99d0adda2a744d4"),
"authorName" : "author name8",
"email" : "email8#email.com",
"c" : 8
},
{
"_id" : ObjectId("512fa900d99d0adda2a744d3"),
"authorName" : "author name7",
"email" : "email7#email.com",
"c" : 7
},
{
"_id" : ObjectId("512fa900d99d0adda2a744d2"),
"authorName" : "author name6",
"email" : "email6#email.com",
"c" : 6
}
],
"total" : 25
}
],
"ok" : 1
}
By the end, I think that for big collection 2 query (first for data, second for count) works faster. For example, you can count total for collection like this:
db.so.count()
or like this:
db.so.find({},{_id:1}).sort({_id:-1}).count()
I don't fully sure in first example, but in second example we use only cursor, which means higher speed:
db.so.find({},{_id:1}).sort({_id:-1}).explain()
{
"cursor" : "BtreeCursor _id_ reverse",
"isMultiKey" : false,
"n" : 25,
"nscannedObjects" : 25,
"nscanned" : 25,
"nscannedObjectsAllPlans" : 25,
"nscannedAllPlans" : 25,
"scanAndOrder" : false,
!!!!!>>> "indexOnly" : true, <<<!!!!!
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 0,
...
}

For completeness (full discussion was on the MongoDB Google Groups) here is the aggregation you want:
db.collection.aggregate(db.docs.aggregate( [
{
"$match" : {
"year" : "2012"
}
},
{
"$group" : {
"_id" : null,
"my_documents" : {
"$push" : {
"_id" : "$_id",
"year" : "$year",
"author" : "$author"
}
},
"reviewsCount" : {
"$sum" : 1
}
}
},
{
"$project" : {
"_id" : 0,
"my_documents" : 1,
"total" : "$reviewsCount"
}
}
] )
By the way, you don't need aggregation framework here - you can just use a regular find. You can get count() from a cursor without having to re-query.