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Mongodb Java query for date range

I needed to find all the records in mongo db within two date ranges using Mongo Driver[3.4.0] for Java.
Example:
I have books Collection.
{
"_id" : ObjectId("5acb40d27d63b61cb002bafe"),
"title" : "WingsOfFire",
"pub-date" : ISODate("2013-10-02T00:00:00.000Z"),
"rel-date" : ISODate("2013-11-02T00:00:00.000Z")
}
Like above I have 100s of documents.
I need to find all records wherein pub-date > rel-date.
I am using Mongo DB version 3.2.6
I tried to use $expr operator but it seems to work with only Mongo 3.6+
Not able find cleaner solutions for above requirement.
Please clarify.

The MongoDB (prior to v3.4) shell command for your use case is:
db.collection.aggregate([
{
"$redact": {
"$cond": [
{ "$gt": [ "$pub-date", "$rel-date" ] },
"$$KEEP",
"$$PRUNE"
]
}
}
])
Translating this command into Java you'll get:
MongoClient mongoClient = ...;
MongoCollection<Document> collection = mongoClient.getDatabase("...").getCollection("...");
List<Document> documents = collection.aggregate(Arrays.asList(
new Document("$redact", new Document("$cond",
Arrays.asList(new Document("$gt", Arrays.asList("$pub-date", "$rel-date")), "$$KEEP", "$$PRUNE"))
))).into(new ArrayList<>());
for (Document document : documents) {
System.out.println(document.toJson());
}
Given a collection with these documents ...
{
"_id" : ObjectId("5acb40d27d63b61cb002bafe"),
"title" : "WingsOfFire",
"pub-date" : ISODate("2013-10-02T00:00:00.000Z"),
"rel-date" : ISODate("2013-11-02T00:00:00.000Z")
}
{
"_id" : ObjectId("5acb662756539a6734e64e4a"),
"title" : "WingsOfSmoke",
"pub-date" : ISODate("2013-11-02T00:00:00.000Z"),
"rel-date" : ISODate("2013-10-02T00:00:00.000Z")
}
.. the above Java code will print ...
{ "_id" : { "$oid" : "5acb662756539a6734e64e4a" }, "title" : "WingsOfSmoke", "pub-date" : { "$date" : 1383350400000 }, "rel-date" : { "$date" : 1380672000000 } }
... because this document's pub-date (2013-11-02T00:00:00.000Z) is after its rel-date (2013-10-02T00:00:00.000Z).
Note: the $where operator is functionally equivalent but use of that operator comes with some limitations:
$where evaluates JavaScript and cannot take advantage of indexes. Therefore, query performance improves when you express your query using the standard MongoDB operators (e.g., $gt, $in).
In general, you should use $where only when you can’t express your query using another operator. If you must use $where, try to include at least one other standard query operator to filter the result set. Using $where alone requires a collection scan.

You might want to try $where-Operator:
db.books.find({ "$where": "this.pub-date > this.rel-date"});

MongoDB - strange behaviour of query

I have this two documents in my mongoDB database:
db.DocumentFile.find().pretty()
{
"_id" : ObjectId("587f39910cc0fec092bdb10c"),
"_class" : "com.smartinnotec.legalprojectmanagement.dao.domain.DocumentFile",
"fileName" : "DocumentFile1",
"ending" : "jpg",
"projectId" : "587f39910cc0fec092bdb10b",
"active" : true,
"userIdBlackList" : [
"587f39910cc0fec092bdb10a"
]
}
{
"_id" : ObjectId("587f39910cc0fec092bdb10d"),
"_class" : "com.smartinnotec.legalprojectmanagement.dao.domain.DocumentFile",
"fileName" : "DocumentFile2",
"ending" : "jpg",
"projectId" : "587f39910cc0fec092bdb10b",
"active" : true,
"userIdBlackList" : [ ]
}
I have this code in order to get amount of query:
final Query query = new Query();
query.addCriteria(Criteria.where("‌​userIdBlackList").nin(userId));
final Long amount = mongoTemplate.count(query, DocumentFile.class);
return amount.intValue();
The amount is 2 in this case what is wrong - it should be 1.
The query in Query object looks like this:
Query: { "‌​userIdBlackList" : { "$nin" : [ "587f39910cc0fec092bdb10a"]}}
If I copy this query and made a query for the mongodb console like this:
db.DocumentFile.find({ "‌​userIdBlackList" : { "$nin" : [ "587f39910cc0fec092bdb10a"]}}).pretty()
I get an amount of two, what if wrong because one document includes 587f39910cc0fec092bdb10a in userIdBlackList -> it should be one.
With this query command:
db.DocumentFile.find({userIdBlackList: { "$nin": ["587f39910cc0fec092bdb10a"] } }).pretty();
I get the right result, I am really confused at the moment.
Does anyone have any idea?
Maybe the problem ist that one time userIdBlackList is with quotation mark ("userIdBlackList") and the other time it isn't.

I think the problem is with the unintentional formatting picked up for "userIdBlackList". Your string is interpreted with non printing characters in the "??userIdBlackList" for all your search queries. I see little transparent square boxes when I copy your queries to mongo shell.
That tells me their is some encoding issue. Clear that formatting and see if that helps you.
Both $ne and $nin should work!

Change Value of Nested Object - MongoDB Java

I'm making a MongoDB statistic system using the Java driver, and I am wondering if it is possible (and how) to change the value of a key nested inside many objects. Here is how my database is formatted:
{
location : “chicago”,
stats : [
{
"employee" : "rob",
"stat1" : 1,
"stat2" : 3,
"stat3" : 2
},
{
"employee" : "krista",
"stat1" : 1,
"stat2" : 3,
"stat3" : 2
}
]
}
So, for example, how could I change Rob's "stat2" to another value? I am new to JSON and the MongoDB Java driver. Any help is appreciated!

You need to use the positional $ operator and $set in order to update what you want.
db.collection.update(
{ _id: <docId>, "stats.employee": "rob" },
{ "$set": { "stats.$.stat2": <value> } }
)
So you match your document and the required element of the array. The update side uses that array index to know in which element to update. The $set operator only updates the specified field.
In Java, Build with BasicDBObject.
BasicDBObject query = new BasicDBObject("_id", id);
query.append( new BasicDBObject("stats.employee", "rob") );
BasicDBObject update = new BasicDBObject("$set",
new BasicDBObject("stats.$.stat2", value));
collection.update(query,update);

Updating Nested Embedded Documents in mongodb

I am new to mongodb. Plz help me with this.
I need a document like this
employee{
_id:111,
name:xxx,
dependents : [ {
name:a,
age:51,
dep_children:[{name:aa}{name:bb}{name:c}]
}
{
name:b,
age:52,
dep_children:[{name:aa}{name:bb}{name:c}]
}
{
name:c,
age:51,
dep_children:[{name:aa}{name:bb}{name:cc}]
}
]
}
I am using the below script to migrate data for SQL and update it into mongoDB
My code looks something like this:
while(personcount>=0)
{
BasicDBObject doc = new BasicDBObject("_id",ind1.get(count)).
append("name",ind2.get(count));
coll.insert(doc);
while(dependentcount>0)
{
BasicDBObject querymongo = new BasicDBObject();
querymongo.put( "name",ind.get(count));
BasicDBObject tenant = new BasicDBObject();
tenant.put("name",indsa.get(innercount) );
tenant.put("age", indsa2.get(innercount));
BasicDBObject update = new BasicDBObject();
update.put("$push", new BasicDBObject("dependents",tenant));
coll.update(querymongo, update,true,true);
while(kidcount>0)
{
BasicDBObject querymongofact = new BasicDBObject();
querymongokid.put( "dependent.name",indsa.get(innercount));
BasicDBObject tenantkid = new BasicDBObject();
tenantkid .put("name",indfact.get(innercountfact) );
BasicDBObject updatekid = new BasicDBObject();
updatekid .put("$push", new BasicDBObject("dependent.dep_children",tenantkid));
coll.update(querymongokid, updatekid ,true,true);
}
}
}
when we print querymongokid and updatekid, the data inside it are expected values itself. This code is not throwing any error. But in data base the only dep_children data is not getting updated . I am not getting wt went wrong. please help me
Thanks in advance

Your last query fails in the mongo driver in a sense that the update has no effect - but it's not an actual error. Just let me reproduce what you are doing in the mongo shell:
> db.coll.insert({_id:1,name:"name1"})
> db.coll.update({name:"name1"}, {"$push": {dependents: {name:"a", age:50}}})
> db.coll.update({name:"name1"}, {"$push": {dependents: {name:"b", age:55}}})
> db.coll.findOne()
{
"_id" : 1,
"dependents" : [
{
"name" : "a",
"age" : 50
},
{
"name" : "b",
"age" : 55
}
],
"name" : "name1"
}
> db.coll.update({"dependents.name": "a"}, {"$push": {"dependents.dep_children": {name:"aa"}}})
can't append to array using string field name: dep_children
> db.coll.update({"dependents.name": "a"}, {"$push": {"dependents.$.dep_children": {name:"aa"}}})
> db.coll.findOne()
{
"_id" : 1,
"dependents" : [
{
"age" : 50,
"dep_children" : [
{
"name" : "aa"
}
],
"name" : "a"
},
{
"name" : "b",
"age" : 55
}
],
"name" : "name1"
}
Unfortunately, I have very little experience with the native mongo java driver (I'm usually on Spring data), but changing your line
updatekid.put("$push", new BasicDBObject("dependent.dep_children",tenantkid));
to
updatekid.put("$push", new BasicDBObject("dependent.$.dep_children",tenantkid));
should do the trick as well.
The reason for that behavior is that "dependent.dep_children" is not a valid selector as it corresponds to "go to field dep_children within the subdocument dependent". However, "dependent" happens to be an array without any fields. The $ replaces an explicit index and will make sure the correct subdocument from your query is selected.
Also see here for a less error-prone formulation of your query - without using $elemMatch it will only work if your query uniquely identifies a certain array element. With $elemMatch it will always work, but only update the first match.

Mongodb: Can't save a new element added into BasicDBList

I am trying to add an element to a BasicDBList array and save it back to Mongodb, but when I check the result, it is not written. What did I do wrong? I use java driver version 2.7.2.
DBObject dbObject = coll.findOne(dbQuery);
BasicDBList unreadMsgs = (BasicDBList) dbObject.get("unreadMsgs");
Logger.debug("before incrementing unreadMsgs" + dbObject.toString());
unreadMsgs.add(new BasicDBObject("id", 1).append("unreadMsg", 1));
Logger.debug("after incrementing unreadMsgs : " + dbObject.toString());
coll.save(dbObject);
Logger.debug("check result: " + coll.findOne(dbQuery).toString());
before incrementing unreadMsgs{ "_id" : { "$oid" : "515c5eb88e3278e9c9d55867"} , "unreadMsgs" : [ ]}
after incrementing unreadMsgs : { "_id" : { "$oid" : "515c5eb88e3278e9c9d55867"} , "unreadMsgs" : [ { "id" : 1 , "unreadMsg" : 1}]}
check result: { "_id" : { "$oid" : "515c5eb88e3278e9c9d55867"} , "unreadMsgs" : [ ]}

The problem is that the coll.save(dbObject) is not updating anything.
It works as an insert and, since the _id already exists in the collection, you are getting a duplicateKey exception (you are just not seeing it because of configuration).
You have to use an update, here is how

The save call should work on that case, but I suggest you use an update with $addToSet operation.
Here's the code:
DBObject addToSetObj = BasicDBObjectBuilder.start()
.push("$addToSet")
.push("unreadMsgs")
.add("id", 1)
.add("unreadMsg", 1)
.pop()
.pop()
.get();
// addToSetObj will be { "$addToSet" : { "unreadMsgs" : { "id" : 1 , "unreadMsg" : 1}}}
coll.update(dbQuery, addToSetObj);
Logger.debug("check result: " + coll.findOne(dbQuery).toString());
Any doubts on how to use addToSet, check this out: http://docs.mongodb.org/manual/reference/operator/addToSet/

Thanks for everybody's answer. I found the real problem. It turns out that my collection is capped, and I am not allowed to insert more data into an existing document in a capped collection. I saw the exception after I changed WriteConcern to FSYNC_SAFE. I changed all my collections to uncapped, and the code works now.