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How to update value of specific embedded document, inside an array, of a specific document in MongoDB?
(4 answers)
Closed 5 years ago.
I have a document in my collection
{
"_id" : ObjectId("59bd65b281a24497a0b3b401"),
"user_id" : "1",
"is_placed" : false,
"items" : [
{
"product_id" : 1,
"units" : 0
},
{
"product_id" : 2,
"units" : 0
}
]
}
I want to increment value of 'units' for product_id = 1. Here is what my code looks like:
MongoClient mongoConnection = new MongoClient("localhost", 27017);
try {
MongoDatabase db = mongoConnection.getDatabase("mydb");
MongoCollection<Document> collection = db.getCollection("orders");
BasicDBObject whereQuery = new BasicDBObject();
whereQuery.put("user_id", "1");
whereQuery.put("is_placed", false);
whereQuery.put("product_id", 1);
BasicDBObject incValue = new BasicDBObject("items.units", 1);
BasicDBObject intModifier = new BasicDBObject("$inc", incValue);
collection.updateOne(whereQuery, intModifier);
} catch (Exception e) {
e.printStackTrace();
}
It does not throw any error. But neither does it increment the value. How do I achieve it? Also, is it possible to increment it only if product_id = 1 exists else put product_id = 1?
For updating an embedded document in an array, you should use $ operator. I cannot see you use it anywhere in your code. Your code may be, should be like this:
MongoClient mongoConnection = new MongoClient("localhost", 27017);
try {
MongoDatabase db = mongoConnection.getDatabase("db");
MongoCollection<Document> collection = db.getCollection("orders");
BasicDBObject whereQuery = new BasicDBObject();
whereQuery.put("user_id", "1");
whereQuery.put("is_placed", false);
whereQuery.put("items.product_id", 1);
BasicDBObject incValue = new BasicDBObject("items.$.units", 1);
BasicDBObject intModifier = new BasicDBObject("$inc", incValue);
collection.updateOne(whereQuery, intModifier);
} catch (Exception e) {
e.printStackTrace();
}
Related
I want to get max timestamp of a set of tags from MongoDb history database. Say the tag ids are 1,2,3,4,5 I want to check all records for these tags and get the timestamp of latest. My collection looks like this along with data:
My code is as follows:
protected Timestamp getMaxRealTimeHistoryTimestamp(List<Integer> tagIds)
{
try
{
MongoClient mongo = new MongoClient(m_connectionInfo.getHost(), m_connectionInfo.getPort());
//Connecting to the database
MongoDatabase database = mongo.getDatabase(m_connectionInfo.getDatabaseName());
BasicDBObject andQuery = new BasicDBObject();
List<BasicDBObject> obj = new ArrayList<>();
obj.add(new BasicDBObject("TAG_ID", new BasicDBObject("$in", tagIds)));
MongoCollection<Document> collection = database.getCollection("EM_HISTORY");
Document doc = collection.find(andQuery).sort(new Document("TIME_STAMP", -1)).first();
if(doc != null)
{
return new Timestamp(((Date) doc.get("TIME_STAMP")).getTime());
}
}
catch (Exception e)
{
if (Logger.isErrorEnabled())
Logger.error(e);
}
return null;
}
the doc variable has some strange row that is not even in the collection
What am I doing wrong here?
BasicDBObject andQuery = new BasicDBObject();
List<BasicDBObject> obj = new ArrayList<>();
obj.add(new BasicDBObject("TAG_ID", new BasicDBObject("$in", tagIds)));
You are never adding the query filters from obj back into your andQuery, so the code ends up querying the collection without any filter.
i am trying transfer the PostgreSQL for MongoDB using java.
I have the SQL
SELECT id_buyer, buyer, SUM(qtde)
FROM test.log
GROUP BY id_buyer, buyer
and my new code
MongoClient mongoClient = new MongoClient();
MongoDatabase db = mongoClient.getDatabase("teste");
MongoCollection<Document> coll = db.getCollection("log");
DBObject groupFields = new BasicDBObject();
groupFields.put("id_buyer", "$id_buyer");
groupFields.put("buyer", "$buyer");
AggregateIterable<Document> mongoCollectionList = coll.aggregate(
Arrays.asList(
Aggregates.group(groupFields, Accumulators.sum("qtde", "$qtde")),
Aggregates.project(fields(include("comprador", "Quantidade")))
));
MongoCursor<Document> mongoCursor = mongoCollectionList.iterator();
while (mongoCursor.hasNext()) {
System.out.println(mongoCursor.next().toJson());
}
result
{ "_id" : { "id_buyer" : 2, "buyer" : "COMPS" }, "qtde" : 16703 }
How do i remove "id_buyer" and "buyer" that is into "_id" ?
Tks
you try like this..
AggregateIterable<Document> mongoCollectionList = collection.aggregate(
Arrays.asList(
Aggregates.group(groupFields, Accumulators.sum("qtde", "$qtde")),
Aggregates.project(Projections.fields(Projections.include("qtde"),Projections.excludeId()))
));
I have tested the answer posted by Veeram and it worked perfectly for me.
This was his sugestion:
Aggregates.project(fields(excludeId(),
computed("id_buyer", "$_id.id_buyer"),
computed("buyer", "$_id.buyer"),
include("comprador", "Quantidade")));
I'm trying to query mongodb with java. The name of my collection is: reads. Here is an example of a specific document I'm querying for:
{
"_id" : {
"d" : "B66929932",
"r" : "15500304",
"eT" : ISODate("2014-09-29T12:03:00Z")
},
"v" : 169000,
"iT" : ISODate("2015-04-10T20:42:07.577Z")
}
I'm trying to query where r = 15500304, eT = 2014-09-29T12:03:00Z and v = 169000. I'm able to do this in mongo pretty easily:
db.reads.find({ "_id.r" : "15500304", "_id.eT" : ISODate("2014-09-29T12:03:00Z"), "$where" : "this.v == 169000;"}).pretty()
I'm unable to figure out how to structure this in java. So far I've got:
DBCollection collection = db.getCollection("reads");
BasicDBObject andQuery = new BasicDBObject();
List<BasicDBObject> obj = new ArrayList<BasicDBObject>();
obj.add(new BasicDBObject("_id.r", "15500304"));
obj.add(new BasicDBObject("_id.eT", "2014-09-29T12:03:00Z"));
obj.add(new BasicDBObject("v", 169000));
andQuery.put("$and", obj);
DBCursor cursor = collection.find(andQuery);
while(cursor.hasNext()){
System.out.println(cursor.next());
}
My Question is: How do I query using these child nodes and return the matching document?
I'm unable to find any clear advice/examples online. Any and all advice is very appreciated.
You were close. Modify your query to:
DBCollection collection = db.getCollection("reads");
BasicDBObject query = new BasicDBObject();
DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
String dateInString = "2014-09-29T12:03:00Z";
Date date = df.parse(dateInString);
query.append("status.name", "Expired")
.append("_id.eT", date)
.append("v", 169000);
Or using QueryBuilder:
DBObject query = QueryBuilder.start()
.put("_id.r").is("15500304")
.put("_id.eT").is(date)
.put("v").is(169000)
.get();
DBCursor cursor = collection.find(query);
while(cursor.hasNext()){
System.out.println(cursor.next());
}
Is there a way in the MongoDB Java driver to call the db.collection.remove(query) method that I see in the MongoDB shell documentation?
That is, I know the exact criteria that I need to find all the documents I want to delete from MongoDB, but I can't find a way to make one call to remove those records in one trip. All that I can figure out is to find the documents and then delete them one by one.
I see this
http://docs.mongodb.org/manual/reference/method/db.collection.remove/
which implies there should be a way to do it, but I can't figure out the Java calls to get me that to that call.
Thank you for your help
To remove documents with an age property of 25.
MongoClient mongo = new MongoClient(new ServerAddress("localhost", 27017));
DB db = mongo.getDB("thedb");
DBCollection collection = db.getCollection("test");
BasicDBObject query = new BasicDBObject();
query.append("age", 25);
collection.remove(query);
DBCollection and BasicDBObject are two of the most important classes in the Java API.
Also to remove specific values from you document you can use following code with Mongo Java 3.2
Document docToDelete = new Document("Designation", "SE-1");
objDbCollection.findOneAndUpdate(new Document("Company", "StackOverflow"), new Document("$unset", docToDelete));
Above code will first find document having company = StackOverflow and then unset (remove) Designation = SE-1 key/value from that document.
Add and Update Mongo
public class App {
public static void main(String[] args) {
try {
Mongo mongo = new Mongo("localhost", 27017);
DB db = mongo.getDB("yourdb");
// get a single collection
DBCollection collection = db.getCollection("dummyColl");
//insert number 1 to 10 for testing
for (int i=1; i <= 10; i++) {
collection.insert(new BasicDBObject().append("number", i));
}
//remove number = 1
DBObject doc = collection.findOne(); //get first document
collection.remove(doc);
//remove number = 2
BasicDBObject document = new BasicDBObject();
document.put("number", 2);
collection.remove(document);
//remove number = 3
collection.remove(new BasicDBObject().append("number", 3));
//remove number > 9 , means delete number = 10
BasicDBObject query = new BasicDBObject();
query.put("number", new BasicDBObject("$gt", 9));
collection.remove(query);
//remove number = 4 and 5
BasicDBObject query2 = new BasicDBObject();
List<Integer> list = new ArrayList<Integer>();
list.add(4);
list.add(5);
query2.put("number", new BasicDBObject("$in", list));
collection.remove(query2);
//print out the document
DBCursor cursor = collection.find();
while(cursor.hasNext()) {
System.out.println(cursor.next());
}
collection.drop();
System.out.println("Done");
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (MongoException e) {
e.printStackTrace();
}
How can I make this query in Java
db.comments.find({ "hsID.$id" { "$oid" : "4fe71a50e7e9f22ae5fb96bf"}} , {commentList: { $slice : [ 2 , 2]}});
This the code I am doing
BasicDBObject query = new BasicDBObject();
BasicDBObject allFields = new BasicDBObject();
ObjectId objectId = new ObjectId(objId);
query.put("{hsID.$id", objectId);
Integer[] sliceInt = { startIndex, pageSize };
query.put(
"commentList",
new BasicDBObject().append("$slice", sliceInt));
DBCursor resultsCursor = CommentColl.find(allFields,query);
and the output is
And the output is
query = { "{hsID.$id" : { "$oid" : "4fe71a50e7e9f22ae5fb96bf"} , "commentList" : { "$slice" : [ 2 , 2]}}
Thanks for your help
You need to separate the query from the fields you want returned. Try something more like this:
BasicDBObject query = new BasicDBObject("hsID.$id", new ObjectId(objId));
BasicDBObject fields = new BasicDBObject(
"commentList",
new BasicDBObject("$slice", new int[] { startIndex, pageSize }));
DBCursor resultsCursor = CommentColl.find(query, fields);
Notice also that I removed the opening curly brace that you had preceding hsid.$id.