I'm trying to find all the documents with first name starting with Ram or Shyam.
I tried the following which actually worked in mongoDb
db.collection.find({
$or: [
{
name: {
$regex: "^Ram"
}
},
{
"name": {
"$regex": "^Shyam"
}
}
]
})
I got around count of 4k documents with this find.
Now when I tried to convert this mongo shell query into java.
Things do work but only name starting with Shyam get filtered. As a result the count also decreases to 2k.
Can someone please look at the below code and tell me why is it happening?
Why things are working in mongodb and not in java.
Java Equivalent Code --
MongoDatabase database = mongoClient.getDatabase("Friends");
MongoCollection<Document> collection = database.getCollection("Friend");
BasicDBObject filter = new BasicDBObject("$or", Arrays.asList
(new BasicDBObject("name", new BasicDBObject("$regex", "^Ram")).append("name", new
BasicDBObject("$regex", "^Shyam"))));
collection.find(filter).forEach((Consumer<Document>) doc -> {
// some java function
}
I figured out. There is just one some thing as $or operator always take array
In my java code I have converted it into array but just forgot that there is no need to append .
The solution will be --
BasicDBObject filter = new BasicDBObject("$or", Arrays.asList
(new BasicDBObject("name", new BasicDBObject("$regex", "^Ram")),new BasicDbObject("name", new
BasicDBObject("$regex", "^Shyam"))));
collection.find(filter).forEach((Consumer<Document>) doc -> {
// some java function
}
As per your mongo query, you need to match against name field but not on id field. That's the mistake
BasicDBObject filter = new BasicDBObject("$or", Arrays.asList
(new BasicDBObject("name", new BasicDBObject("$regex", "^Ram"))
.append("id", new //Here is the mistake
BasicDBObject("$regex", "^Shyam"))));
It should be
BasicDBObject filter = new BasicDBObject("$or", Arrays.asList
(new BasicDBObject("name", new BasicDBObject("$regex", "^Ram"))
.append("name", new BasicDBObject("$regex", "^Shyam"))));
Related
I want to execute query in MongoDB 3.2 with Java Driver 3.2, which contains both $and and $or clauses at the same time.
With the reference, I tried the following approach:
List<Document> criteria1 = new ArrayList<>();
List<Document> criteria2 = new ArrayList<>();
criteria1.add(new Document("fetchStatus", new Document("$gte", FetchStatus.PROCESSED_NLP.getID())));
criteria1.add(new Document("fetchStatus", new Document("$lte", fetchStatusParam)));
criteria1.add(new Document("episodeID", new Document("$in", episodeIDs)));
criteria2.add(new Document("fetchStatus", new Document("$eq", PROCESSED_FETCH.getID())));
criteria2.add(new Document("isFullTextRet", new Document("$eq", false)));
BasicDBList or = new BasicDBList();
or.add(criteria1);
or.add(criteria2);
DBObject query = new BasicDBObject("$or", or);
ArrayList<Document> results = dbC_Coll.find(query).into(new ArrayList<>());
Where the criteria1 and criteria2 should be connected with $or while within criteria1 clause the $and should be applied.
The problem is that in MongoDB Java Driver 3.2 there is such no method and I get the Cannot resolve method find(com.mongodb.DBObject) error.
How can I compose a query such as (A && B) || (X && Y) in MongoDB Java Driver 3.2?
Personally, I find it far less confusing to construct the object sequences just like U would with a JSON structure to enhance readability. But it's still just Document() wherever you see {} and List wherever you see []:
Document query = new Document(
"$or", Arrays.asList(
// First document in $or
new Document(
"fetchStatus",
new Document( "$gte", FetchStatus.PROCESSED_NLP.getID() )
.append("$lte", fetchStatusParam)
)
.append("episodeID", new Document( "$in", episodeIDs)),
// Second document in $or
new Document("fetchStatus", PROCESSED_FETCH.getID())
.append("isFullTextRet", false)
)
);
Which is basically the same as:
{
"$or": [
{
"fetchStatus": {
"$gte": FetchStatus.PROCESS_NLP.getID(),
"$lte": fetchStatusParam
},
"episodeID": { "$in": episodeIDs }
},
{
"fetchStatus": PROCESSED_FETCH.getID(),
"isFullTextRet": false
}
]
}
Also there is no need for "explicit" $eq operators, since "equals" is actually the default meaning of a value assignment in a query property anyway.
I want to perform a query on a field that is greater than or equal to, AND less than or equal to(I'm using java btw). In other words. >= and <=. As I understand, mongoDB has $gte and $lte operators, but I can't find the proper syntax to use it. The field i'm accessing is a top-level field.
I have managed to get this to work:
FindIterable<Document> iterable = db.getCollection("1dag").find(new Document("timestamp", new Document("$gt", 1412204098)));
as well ass...
FindIterable<Document> iterable = db.getCollection("1dag").find(new Document("timestamp", new Document("$lt", 1412204098)));
But how do you combine these with each other?
Currently I'm playing around with a statement like this, but it does not work:
FindIterable<Document> iterable5 = db.getCollection("1dag").find(new Document( "timestamp", new Document("$gte", 1412204098).append("timestamp", new Document("$lte",1412204099))));
Any help?
Basically you require a range query like this:
db.getCollection("1dag").find({
"timestamp": {
"$gte": 1412204098,
"$lte": 1412204099
}
})
Since you need multiple query conditions for this range query, you can can specify a logical conjunction (AND) by appending conditions to the query document using the append() method:
FindIterable<Document> iterable = db.getCollection("1dag").find(
new Document("timestamp", new Document("$gte", 1412204098).append("$lte", 1412204099)));
The constructor new Document(key, value) only gets you a document with one key-value pair. But in this case you need to create a document with more than one. To do this, create an empty document, and then add pairs to it with .append(key, value).
Document timespan = new Document();
timespan.append("$gt", 1412204098);
timespan.append("$lt", 1412204998);
// timespan in JSON:
// { $gt: 1412204098, $lt: 1412204998}
Document condition = new Document("timestamp", timespan);
// condition in JSON:
// { timestamp: { $gt: 1412204098, $lt: 1412204998} }
FindIterable<Document> iterable = db.getCollection("1dag").find(condition);
Or if you really want to do it with a one-liner without temporary variables:
FindIterable<Document> iterable = db.getCollection("1dag").find(
new Document()
.append("timestamp", new Document()
.append("$gt",1412204098)
.append("$lt",1412204998)
)
);
Can anyone explain me why in Java when i do an aggregation pipeline with "$out" don't write the result in the new collection when i write only this:
Document match = new Document("$match", new Document("top_speed",new Document("$gte",350)));
Document out=new Document("$out", "new_collection");
coll.aggregate(Arrays.asList(
match,out
)
);
When I save the aggregation result and I iterate on it, the new collection is created and the result of the match is inside (Java has an error obviously in this case):
AggregateIterable<Document> resultAgg=
coll.aggregate(Arrays.asList(
match,out
)
);
for (Document doc : resultAgg){
System.out.println("The result of aggregation match:-"+ doc.toJson());
}
I can't understand why.
You can call toCollection() method instead of iterating.
Document match = new Document("$match", new Document("top_speed", new Document("$gte", 350)));
Document out = new Document("$out", "new_collection");
coll.aggregate(Arrays.asList(match, out)).toCollection();
I'm trying to query and sort documents as followed:
Query only for documents older than SOMETIME.
Within range of AROUNDME_RANGE_RADIUS_IN_RADIANS.
Get distance for each document.
Sort them by time. New to Old.
Overall it should return up to 20 results.
But it seems that since $geoNear is by default limited to 100 results, I get unexpected results.
I see $geoNear working in the following order:
Gets docs from the entire collection, by distance.
And only then executes the given Query.
Is there a way to reverse the order?
MongoDB v2.6.5
Java Driver v2.10.1
Thank you.
Example document in my collection:
{
"timestamp" : ISODate("2014-12-27T06:52:17.949Z"),
"text" : "hello",
"loc" : [
34.76701564815013,
32.05852053407342
]
}
I'm using aggregate since from what I understood it's the only way to sort by "timestamp" and get the distance.
BasicDBObject query = new BasicDBObject("timestamp", new BasicDBObject("$lt", SOMETIME));
// aggregate: geoNear
double[] currentLoc = new double[] {
Double.parseDouble(myLon),
Double.parseDouble(myLat)
};
DBObject geoNearFields = new BasicDBObject();
geoNearFields.put("near", currentLoc);
geoNearFields.put("distanceField", "dis");
geoNearFields.put("maxDistance", AROUNDME_RANGE_RADIUS_IN_RADIANS));
geoNearFields.put("query", query);
//geoNearFields.put("num", 5000); // FIXME: a temp solution I would really like to avoid
DBObject geoNear = new BasicDBObject("$geoNear", geoNearFields);
// aggregate: sort by timestamp
DBObject sortFields = new BasicDBObject("timestamp", -1);
DBObject sort = new BasicDBObject("$sort", sortFields);
// aggregate: limit
DBObject limit = new BasicDBObject("$limit", 20);
AggregationOutput output = col.aggregate(geoNear, sort, limit);
You could add a $match stage at the top of the pipleine, to filter the documents before the $geonear stage.
BasicDBObject match = new BasicDBObject("timestamp",
new BasicDBObject("$lt", SOMETIME));
AggregationOutput output = col.aggregate(match,geoNear, sort, limit);
The below piece of code now, is not required,
geoNearFields.put("query", query);
I have the following structure in my document:
{
_id : ObjectId("43jh4j343j4j"),
array : [
{
_arrayId : ObjectId("dsd87dsa9d87s9d7"),
someField : "something",
someField2 : "something2"
},
{
_arrayId : ObjectId("sds9a0d9da0d9sa0"),
someField : "somethingElse",
someField2 : "somethingElse2"
}
]
}
I want to update someField and someField2 but only for one of the items in the array, the one that matches _arrayId (e.g. _arrayId : ObjectId("dsd87dsa9d87s9d7"); and only for this document (e.g. _id : ObjectId("43jh4j343j4j") ) and no other.
The arrayIds are not unique to the document that's why I need it to be for a specific document. I could use the $ positional operator if I wanted to update that value within the array for every document it exists in, but that's not what I want.
I am trying to accomplish this in java but a command line solution would work as well.
Here is RameshVel's solution translated to java:
DB db = conn.getDB( "yourDB" );
DBCollection coll = db.getCollection( "yourCollection" );
ObjectId _id = new ObjectId("4e71b07ff391f2b283be2f95");
ObjectId arrayId = new ObjectId("4e639a918dca838d4575979c");
BasicDBObject query = new BasicDBObject();
query.put("_id", _id);
query.put("array._arrayId", arrayId);
BasicDBObject data = new BasicDBObject();
data.put("array.$.someField", "updated");
BasicDBObject command = new BasicDBObject();
command.put("$set", data);
coll.update(query, command);
You could still use $ positional operator to accomplish this. But you need to specify the objectid of the parent doc along with the _arrayid filter. The below command line query works fine
db.so.update({_id:ObjectId("4e719eb07f1d878c5cf7333c"),
"array._arrayId":ObjectId("dsd87dsa9d87s9d7")},
{$set:{"array.$.someField":"updated"}})
...and this is how to do it with mongo-driver version >= 3.1 (mine is 3.2.2):
final MongoClient mongoClient = new MongoClient(new MongoClientURI(mongoURIString));
final MongoDatabase blogDatabase = mongoClient.getDatabase("yourDB");
MongoCollection<Document> postsCollection = blogDatabase.getCollection("yourCollection");
ObjectId _id = new ObjectId("4e71b07ff391f2b283be2f95");
ObjectId arrayId = new ObjectId("4e639a918dca838d4575979c");
Bson filter = Filters.and(Filters.eq( "_id", id ), Filters.eq("array._arrayId", arrayId));
Bson setUpdate = Updates.set("array.$.someField", "updated");
postsCollection.updateOne(postFilter, setUpdate);
Seeing as none of the answers actually explain how to do this a) in Java and b) for multiple fields in a nested array item, here is the solution for mongo-java-driver 3.12.3.
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.Updates;
import org.bson.Document;
import org.bson.types.ObjectId;
MongoClient mongoClient = MongoClients.create(...);
MongoDatabase db = mongoClient.getDatabase("testDb");
MongoCollection<Document> collection = db.getCollection("testCollection");
collection.updateOne(
Filters.and(
Filters.eq("_id", new ObjectId("43jh4j343j4j")),
Filters.eq("array._arrayId", new ObjectId("dsd87dsa9d87s9d7"))
),
Updates.combine(
Updates.set("array.$.someField", "new value 1"),
Updates.set("array.$.someField2", "new value 2")
)
);
This thread has helped me towards the right solution, but I had to do more research for the full solution, so hoping that someone else will benefit from my answer too.