Here is the sample document of my MongoDB:
user:{
_id:1,
name:'xyz',
age:12,
mobile:21321312,
transaction:[{
trans_id:1,
prod:'a',
purchasedAt:ISODate("2015-02-01"),
},
{
trans_id:2,
prod:'b',
purchasedAt:ISODate("2015-02-01")
},
{
trans_id:3,
prod:'c',
purchasedAt:ISODate("2014-11-24")
}]
,...
}
My query looks like:
db.user.find({transaction:{$elemMatch:{prod:'a', purchasedAt:ISODate("2015-02-01")}}, transaction:{$elemMatch:{prod:{$nin:['b','c']}, purchasedAt:ISODate("2015-02-01")}}}).count()
I am trying to get the user count who have purchased product 'a' on date "2015-02-01" but not have purchased product b & c on same day.
So while trying to do this in Java with the query:
coll.find(new BasicDBObject().append("transaction", new BasicDBObject("$elemMatch", new BasicDBObject("prod", 'a').append("purchasedAt", Date))).append("transaction", new BasicDBObject("$elemMatch", new BasicDBObject("prod", new BasicDBObject("$nin",['b','c'])).append("purchasedAt", Date)));
I have also tried:
coll.find(new BasicDBObject("transaction", new BasicDBObject("$elemMatch", new BasicDBObject("prod", 'a').append("purchasedAt", Date))).append("transaction", new BasicDBObject("$elemMatch", new BasicDBObject("prod", new BasicDBObject("$nin",['b','c'])).append("purchasedAt", Date)));
where Date is "2015-02-01" in util.Date object.
I found out that Java ignores the $in part of the query, i.e. it ignores {transaction:{$elemMatch:{prod:'a', purchasedAt:ISODate("2015-02-01")}} & performs only $nin part.
I found out it by DBCursor object.
Here's the output of the cursor:
Cursor: Cursor id=0, ns=mydb.user, query={ "transaction" : { "$elemMatch" : { "prod" : { "$nin" : [ "b" , "c"]} , "purchasedAt" : { "$date" : "2015-02-01T00:00:00.000Z"}}}}, numIterated=0, readPreference=primary
Because of this my result is inaccurate. I wonder why the exact same query works well in Mongo shell but doesn't with Java API. Is there anything wrong with my query structure?
My guess is that this question is now moot, but, if you still do not consider it answered, are you looking for the "$not" operator, which can check for non-existance sort of.
I need two to add new items to the existing data in mongo db.
This is mongo db I have the following data.
{
"_id" : ObjectId("53ce11e7d0881d32d9fa935f"),
"name" : "massive riots",
"lastFeachedTime" : "Jul 15, 2014 12:55:27 PM"
}
Here I have to find the data based on name and the I have to add another two items two it.
Here is my code.
DBObject queryObject = new BasicDBObject().append("name", keyword);
if (null == newFetchTime) {
}
DBObject updateObject = new BasicDBObject();
updateObject.put("nextPageToken", nextPageToken);
updateObject.put("prevPageToken", prevPageToken);
Utils utils = new Utils();
DBCollection collection = utils.getStaging().getCollection("test");
collection.update(queryObject, updateObject, true, false);
But I am do update the existing value get removed and the new data get added.
Can any one tell me how to add the items to the existing data in mongo db.
You want the $set operator in your update. This allows the specified fields to be altered without affecting any of the existing fields in the document, unless the specified field exists in which case that field is overwritten:
DBObject update = new BasicDBObject(
"$set", new BasicDBObject()
.append("nextPageToken",nextPageToken)
.append("prevPageToken",prevPageToken)
);
Works out to the equivalent in shell:
{ "$set" : { "nextPageToken" : nextPageToken , "prevPageToken" : prevPageToken }}
Here is a simple pojo:
public class Description {
private String code;
private String name;
private String norwegian;
private String english;
}
And please see the following code to apply an upsert to MongoDb via spring MongoTemplate:
Query query = new Query(Criteria.where("code").is(description.getCode()));
Update update = new Update().set("name", description.getName()).set("norwegian", description.getNorwegian()).set("english", description.getEnglish());
mongoTemplate.upsert(query, update, "descriptions");
The line to generate the Update object specifies every field of the Item class manually.
But if my Item object changes then my Dao layer breaks.
So is there a way to avoid doing this, so that all fields from my Item class are applied automatically to the update?
E.g.
Update update = new Update().fromObject(item);
Note that my pojo does not extend DBObject.
I found a pretty good solution for this question
//make a new description here
Description d = new Description();
d.setCode("no");
d.setName("norwegian");
d.setNorwegian("norwegian");
d.setEnglish("english");
//build query
Query query = new Query(Criteria.where("code").is(description.getCode()));
//build update
DBObject dbDoc = new BasicDBObject();
mongoTemplate.getConverter().write(d, dbDoc); //it is the one spring use for convertions.
Update update = Update.fromDBObject(dbDoc);
//run it!
mongoTemplate.upsert(query, update, "descriptions");
Plz note that Update.fromDBObject return an update object with all fields in dbDoc. If you just want to update non-null fields, you should code a new method to exclude null fields.
For example, the front-end post a doc like below:
//make a new description here
Description d = new Description();
d.setCode("no");
d.setEnglish("norwegian");
We only need to update the field 'language':
//return Update object
public static Update fromDBObjectExcludeNullFields(DBObject object) {
Update update = new Update();
for (String key : object.keySet()) {
Object value = object.get(key);
if(value!=null){
update.set(key, value);
}
}
return update;
}
//build udpate
Update update = fromDBObjectExcludeNullFields(dbDoc);
The solution for a new spring-data-mongodb version 2.X.X.
The API has evolved, since 2.X.X version there is:
Update.fromDocument(org.bson.Document object, String... exclude)
instead of (1.X.X):
Update.fromDBObject(com.mongodb.DBObject object, String... exclude)
The full solution:
//make a new description here
Description d = new Description();
d.setCode("no");
d.setName("norwegian");
d.setNorwegian("norwegian");
d.setEnglish("english");
Query query = new Query(Criteria.where("code").is(description.getCode()));
Document doc = new Document(); // org.bson.Document
mongoTemplate.getConverter().write(item, doc);
Update update = Update.fromDocument(doc);
mongoTemplate.upsert(query, update, "descriptions");
It works!
you can use save : (if non exist = insert else = upsert)
save(Object objectToSave, String collectionName)
read : javadoc
Just like previous answers said, use mongoTemplate.getConverter().write() and Update.fromDocument() functions. But i found Update.fromDocument() won't add "$set" key and won't work directly, the solution is to add "$set" yourself, like below (PS: I'm using 2.2.1.RELEASE version):
public static Update updateFromObject(Object object, MongoTemplate mongoTemplate) {
Document doc = new Document();
mongoTemplate.getConverter().write(object, doc);
return Update.fromDocument(new Document("$set", doc));
}
If you want to upsert Pojos incl. property String id; you have to exclude the _id field in the fromDBObject method Update.fromDBObject(dbDoc,"_id").
Otherwise you get the Exception:
org.springframework.dao.DuplicateKeyException: { "serverUsed" : "127.0.0.1:27017" , "ok" : 1 , "n" : 0 , "updatedExisting" : false , "err" : "E11000 duplicate key error collection: db.description index: _id_ dup key: { : null }" , "code" : 11000}; nested exception is com.mongodb.MongoException$DuplicateKey: { "serverUsed" : "127.0.0.1:27017" , "ok" : 1 , "n" : 0 , "updatedExisting" : false , "err" : "E11000 duplicate key error collection: db.description index: _id_ dup key: { : null }" , "code" : 11000}
because the _id field of the first is null
{
"_id" : null,
...
}
Fullcode based on #PaniniGelato answer would be
public class Description(){
public String id;
...
}
Description d = new Description();
d.setCode("no");
d.setName("norwegian");
d.setNorwegian("norwegian");
d.setEnglish("english");
//build query
Query query = new Query(Criteria.where("code").is(description.getCode()));
//build update
DBObject dbDoc = new BasicDBObject();
mongoTemplate.getConverter().write(d, dbDoc); //it is the one spring use for convertions.
Update update = Update.fromDBObject(dbDoc, "_id");
//run it!
mongoTemplate.upsert(query, update, "descriptions");
Then the upsert is working in the cases of insert and update. Corrections & thoughts are welcome ;)
This is what I am doing for the time being. Not so much elegant way to do it, but it does save a precious DB call:
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Query;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.util.JSON;
/**
* Perform an upsert operation to update ALL FIELDS in an object using native mongo driver's methods
* since mongoTemplate's upsert method doesn't allow it
* #param upsertQuery
* #param object
* #param collectionName
*/
private void performUpsert(Query upsertQuery, Object object, String collectionName){
ObjectMapper mapper = new ObjectMapper();
try {
String jsonStr = mapper.writeValueAsString(object);
DB db = mongoTemplate.getDb();
DBCollection collection = db.getCollection(collectionName);
DBObject query = upsertQuery.getQueryObject();
DBObject update = new BasicDBObject("$set", JSON.parse(jsonStr));
collection.update(query, update, true, false);
} catch (IOException e) {
LOGGER.error("Unable to persist the metrics in DB. Error while parsing object: {}", e);
}
}
There are two cases here that need to be distinguished:
Update an item that was previously fetched from the DB.
Update or insert (upsert) an item you created by code.
In Case 1) You can simply use mongoTemplate.save(pojo, "collection"), because your POJO will already have a filled ObjectID in its id field.
In case 2) You have to explain to mongo what "already exists" means in case of your domain model: By default the mongoTemplate.save() method updates an existing item, if there is one with that same ObjectId. But with a newly instantiated POJO you do not have that id. Therefore the mongoTemplate.upsert() method has a query parameter that you can create like this:
MyDomainClass pojo = new MyDomainClass(...);
Query query = Query.query(Criteria.where("email").is("user1#domain.com"));
DBObject dbDoc = new BasicDBObject();
mongoTemplate.getConverter().write(pojo, dbDoc); //it is the one spring use for convertions.
dbDoc.removeField("_id"); // just to be sure to not create any duplicates
Update update = Update.fromDBObject(dbDoc);
WriteResult writeResult = mongoTemplate.upsert(query, update, UserModel.class);
I ran into the same problem. In het current Spring Data MongoDB version no such thing is available. You have to update the seperate fields by hand.
However it is possible with another framework: Morphia.
This framework has a wrapper for DAO functionality: https://github.com/mongodb/morphia/wiki/DAOSupport
You can use the DAO API to do things like this:
SomePojo pojo = daoInstance.findOne("some-field", "some-value");
pojo.setAProperty("changing this property");
daoInstance.save(pojo);
I think that:
Description add a property
#Id
private String id;
then get a document by the query condition,set Description's id by document's id.
and save
Just use ReflectionDBObject - if you make Description extend it, you should just get your object's fields transferred to Update reflectively, automagically. The note from above about null fields included in the update still holds true.
public void saveOrUpdate(String json) {
try {
JSONObject jsonObject = new JSONObject(json);
DBObject update1 = new BasicDBObject("$set", JSON.parse(json));
mongoTemplate.getCollection("collectionName").update(new Query(Criteria.where("name").is(jsonObject.getString("name"))).getQueryObject(), update1, true, false);
} catch (Exception e) {
throw new GenericServiceException("Error while save/udpate. Error msg: " + e.getMessage(), e);
}
}
this is very simple way to save json string into collection using mongodb
and spring.
This method can be override to use as JSONObject.
#Override
public void updateInfo(UpdateObject algorithm) {
Document document = new Document();
mongoTemplate.getConverter().write(algorithm, document);
Update update = Update.fromDocument(document);
mongoTemplate.updateFirst(query(where("_id").is(algorithm.get_id())), update, UpdateObject.class);
}
After upsert, I was Tring to fetch same record but it was given me the old one.
But in dB I am having new records.
I have a doc in my mongodb that looks like this -
public class AppCheckInRequest {
private String _id;
private String uuid;
private Date checkInDate;
private Double lat;
private Double lon;
private Double altitude;
}
The database will contain multiple documents with the same uuid but different checkInDates
Problem
I would like to run a mongo query using java that gives me one AppCheckInRequest doc(all fields) per uuid who's checkInDate is closest to the current time.
I believe I have to the aggregation framework, but I can't figure out how to get the results I need. Thanks.
In the mongo shell :-
This will give you the whole groupings:
db.items.aggregate({$group : {_id : "$uuid" , value : { $push : "$somevalue"}}} )
And using $first instead of $push will only put one from each (which is what you want i think?):
db.items.aggregate({$group : {_id : "$uuid" , value : { $first : "$somevalue"}}} )
Can you translate this to the Java api? or i'll try to add that too.
... ok, here's some Java:
Assuming the docs in my collection are {_id : "someid", name: "somename", value: "some value"}
then this code shows them grouped by name:
Mongo client = new Mongo("127.0.0.1");
DBCollection col = client.getDB("ajs").getCollection("items");
AggregationOutput agout = col.aggregate(
new BasicDBObject("$group",
new BasicDBObject("_id", "$name").append("value", new BasicDBObject("$push", "$value"))));
Iterator<DBObject> results = agout.results().iterator();
while(results.hasNext()) {
DBObject obj = results.next();
System.out.println(obj.get("_id")+" "+obj.get("value"));
}
and if you change $push to $first, you'll only get 1 per group. You can then add the rest of the fields once you get this query working.
I am trying to get the value of a key from a sub-document and I can't seem to figure out how to use the BasicDBObject.get() function since the key is embedded two levels deep. Here is the structure of the document
File {
name: file_1
report: {
name: report_1,
group: RnD
}
}
Basically a file has multiple reports and I need to retrieve the names of all reports in a given file. I am able to do BasicDBObject.get("name") and I can get the value "file_1", but how do I do something like this BasicDBObject.get("report.name")? I tried that but it did not work.
You should first get the "report" object and then access its contents.You can see the sample code in the below.
DBCursor cur = coll.find();
for (DBObject doc : cur) {
String fileName = (String) doc.get("name");
System.out.println(fileName);
DBObject report = (BasicDBObject) doc.get("report");
String reportName = (String) report.get("name");
System.out.println(reportName);
}
I found a second way of doing it, on another post (didnt save the link otherwise I would have included that).
(BasicDBObject)(query.get("report")).getString("name")
where query = (BasicDBObject) cursor.next()
You can also use queries, as in the case of MongoTemplate and so on...
Query query = new Query(Criteria.where("report.name").is("some value"));
You can try this, this worked for me
BasicDBObject query = new BasicDBObject("report.name", "some value");