So I have a list of queryObjects (a class I created in my program) to query from a mongo DB with expressions all in an object like (pseudo code):
queryObject : { fild, operation, expression }
example : queryObject : { field : "pagePath", operation:"$in", expression:"/home"}
And the user can create as many queries as he/she wants. This works like charm until I have two queries with the same field name, example:
queryObject1 : { field : "pagePath", operation:"$in", expression:"/home"}
queryObject2 : { field : "pagePath", operation:"$regex", expression:"(.html)$"}
than I have: query.put(queryObject1) and query.put(queryObject2)
this command:
FindIterable<Document> iterable = statistics.find(query).projection(excludeId());
takes into consideration only the second put, what made me think that maybe it overrides the first. What can I do to prevent this from happening? is there a query syntaxe in Mongo that allows me to test that the Page Path is both a Home Page and ends with .html? knowing that this condition can change I always have to read the Query Object and create a MongoQuery in my program.
Assuming that your query object basically generates a Bson which can be used for Collection.find(), you can combine multiple Bsons via the Filters-utilities:
Bson b1 = firstQuery.convertToDbQuery(); // or however you do it... ;-)
Bson b2 = secondQuery.convertToDbQuery();
Bson combinedAsAnd = Filters.and(b1, b2);
collection.find(combinedAsAnd).projection(...)
Related
I'm using jongo API - org.jongo.MongoCollection is the class.
I have list of object ids and converted the same as ObjectId[] and trying to query as follows
collection.find("{_id:{$in:#}}", ids).as(Employee.class);
The query throws the exception - "java.lang.IllegalArgumentException: Too
many parameters passed to query: {"_id":{"$in":#}}"
The query doesn't work as specified in the URL In Jongo, how to find multiple documents from Mongodb by a list of IDs
Any suggestion on how to resolve?
Thanks.
Try it with a List as shown on the docs:
List<String> ages = Lists.newArrayList(22, 63);
friends.find("{age: {$in:#}}", ages); //→ will produce {age: {$in:[22,63]}}
For example the following snippet I crafted quick & dirty right now worked for me (I use older verbose syntax as I am currently on such a system ...)
List<ObjectId> ids = new ArrayList<ObjectId>();
ids.add(new ObjectId("57bc7ec7b8283b457ae4ef01"));
ids.add(new ObjectId("57bc7ec7b8283b457ae4ef02"));
ids.add(new ObjectId("57bc7ec7b8283b457ae4ef03"));
int count = friends.find("{ _id: { $in: # } }", ids).as(Friend.class).count();
I'm trying to do upsert using mongodb driver, here is a code:
BulkWriteOperation builder = coll.initializeUnorderedBulkOperation();
DBObject toDBObject;
for (T entity : entities) {
toDBObject = morphia.toDBObject(entity);
builder.find(toDBObject).upsert().replaceOne(toDBObject);
}
BulkWriteResult result = builder.execute();
where "entity" is morphia object. When I'm running the code first time (there are no entities in the DB, so all of the queries should be insert) it works fine and I see the entities in the database with generated _id field. Second run I'm changing some fields and trying to save changed entities and then I receive the folowing error from mongo:
E11000 duplicate key error collection: statistics.counters index: _id_ dup key: { : ObjectId('56adfbf43d801b870e63be29') }
what I forgot to configure in my example?
I don't know the structure of dbObject, but that bulk Upsert needs a valid query in order to work.
Let's say, for example, that you have a unique (_id) property called "id". A valid query would look like:
builder.find({id: toDBObject.id}).upsert().replaceOne(toDBObject);
This way, the engine can (a) find an object to update and then (b) update it (or, insert if the object wasn't found). Of course, you need the Java syntax for find, but same rule applies: make sure your .find will find something, then do an update.
I believe (just a guess) that the way it's written now will find "all" docs and try to update the first one ... but the behavior you are describing suggests it's finding "no doc" and attempting an insert.
Using the MongoDB Java API, I have not been able to successfully locate a full example using text search. The code I am using is this:
DBCollection coll;
String searchString = "Test String";
coll.createIndex(new BasicDBObject ("blogcomments", "text"));
DBObject q = start("blogcomments").text(searchString).get();
The name of my collection that I am performing the search on is blogcomments. creatIndex() is the replacement method for the deprecated method ensureIndex(). I have seen examples for how to use the createIndex(), but not how to execute actual searches with the Java API. Is this the correct way to go about doing this?
That's not quite right. Queries that use indexes of type "text" can not specify a field name at query time. Instead, the field names to include in the index are specified at index creation time. See the documentation for examples. Your query will look like this:
DBObject q = QueryBuilder.start().text(searchString).get();
Can you do parameterized queries with Java and MongoDB - kind of like prepared statements with JDBC?
What I'd like to do is something like this. Set up a query that takes a date range - and then call it with different ranges. I understand that DBCursor.find(...) doesn't work this way - this is kind of pseudo-code to illustrate what I'm looking for.
DBCollection dbc = ...
DBObject pQuery = (DBObject) JSON.parse("{'date' : {'$gte' : ?}, 'date' : {'$lte' : ?}}");
DBCursor aprilResults = dbc.find(pQuery, "2012-04-01", "2012-04-30");
DBCursor mayResults = dbc.find(pQuery, "2012-05-01", "2012-05-31");
...
MongoDB itself doesn't support anything like this, but then again, it doesn't take too much sense as it needs to send the query over to the server every time anyway. You can simply
construct the object in your application yourself, and just modify specific parts by updating the correct array elements.
You should use Jongo, an API over mongo-java-driver.
Here is an example with parameterized query :
collection.insert("{'date' : #}", new Date(999));
Date before = new Date(0);
Date after = new Date(1000);
Iterable<Report> results = collection.find("{'date' : {$gte : #}, 'date' : {$lte : #}}", before, after).as(Report.class);
I have an object that was stored via mongo-java-driver. Object uses java.util.UUID for its _id field. Following is presentation of object via mongo shell:
> db.b.find()
{ "_id" : BinData(3,"zUOYY2AE8WZqigtb/Tqztw==") }
I have a requirement to process searching via $where clause. I use following code to do it:
Mongo m = new Mongo();
DBCollection coll = m.getDB("a").getCollection("b");
coll.save(new BasicDBObject("_id", UUID.randomUUID()));
// ??? - don't know what should be specified
DBObject query = new BasicDBObject("$where", "this[\"_id\"] == " + ???);
coll.find(query).count()
The question is what should I specify instead of ??? to make it work?
Thanks for any help.
My invesigation shown that only one way to do it is rewriting a query in object based way (I mean migration of $where clause part to BasicDBObject based query). In such case mongo-java-driver supports java.util.UUID without any additional effort.