dbref

Is it possible to aggregate on data that is stored via DBRef? Mongo 2.6 Let's say I have transaction data like: { _id : ObjectId(...), user : DBRef("user", ObjectId(...)), product : DBRef("product", ObjectId(...)), source : DBRef("website", ObjectId(...)), quantity : 3, price : 40.95, total_price : 122.85, sold_at : ISODate("2015-07-08T09:09:40.262-0700") } The trick is "source" is polymorphic in nature - it could be different $ref values such as "webpage", "call_center", etc that also have different ObjectIds. For example DBRef("webpage", ObjectId("1")) and DBRef("webpage",ObjectId("2"))

I am using spring-data-mongodb and querydsl-mongodb to perform more flexible queries. My application has users and orders. An user can have multiple orders, so my models looks like this: public class User { @Id private String id; private String username; //getters and setters } public class Order { @Id private String id; @DBRef private User user; //getters and setters } As you can see, there is an has-many relationship between users and orders. Each order is assigned to an user, and the user is stored in @DBRef public User user attribute. Now, lets say that an user has 10,000 orders. How can i

The solution is probably staring me in the face, but I haven't had any luck in finding it. My problem is that I need to find all documents which contain specified DBRef. Here's the structure of the collection to be searched: { "_id" : ObjectId("4e2d4892580fd602eb000003"), "date_added" : ISODate("2011-07-25T11:42:26.395Z"), "date_updated" : ISODate("2011-07-25T11:43:09.870Z"), ... "a_list_of_dbrefs" : [ { "$ref" : "somecollection" "$id" : "4e2d48ab580fd602eb000004" } ], ... "name" : "some name" } I need to be able to retrieve a set of documents based on a DBRef appearing in a_list_of_dbrefs

I am having some troubles with DBRef, look this case: db.fruit.save ({"_id" : "1" , "name" : "apple"}); db.fruit.save ({"_id" : "2" , "name" : "grape"}); db.fruit.save ({"_id" : "3" , "name" : "orange"}); db.fruit.save ({"_id" : "4" , "name" : "pineapple"}); db.basket.save ({"_id" : "1", "items" : [ {"$ref" : "fruit", "$id" : "1", "quantity" : 5}, {"$ref" : "fruit", "$id" : "3", "quantity" : 10} ]}) Now, lets find the "basket" collection: > db.basket.find () { "_id" : "1", "items" : [ { "$ref" : "fruit", "$id" : "1" }, { "$ref" : "fruit", "$id" : "3" } ] } The "quantity" attribute disappeared

Using the DBREF datatype in MongoDB, a document may look like as shown below. But having the $ref field in every row feels redundant as every row obviously points to the users collection. Is there a way to reference other documents without having the somewhat redundant $ref -field? { $id: {$oid : "4f4603820e25f4c515000001"}, title: "User group", users: [ {_id: {$ref: "users", $id: { $oid: "4f44af6a024342300e000002"}}, isAdmin: true } ] ], Dbref in my opinion should be avoided when work with mongodb, at least if you work with big systems that require scalability. As i know all drivers make