Spring Data - Mongo DB - #TextIndexed over #DBRef - mongodb

Is it possible somehow to search in String fields over #DBRef.
I have this #Document:
public class DocumentFileVersion {
#TextIndexed
#DBRef
private OtherObject otherObject
and I will search in String fields of otherObject. Is there any possibility to do that?

DBRef are designed to be queried by id reference only.
So it is not possible. You should rethink your schema structure.

Related

Spring MongoRepository not returning id field of nested objects [duplicate]

I have a document with an array field with
"chapters": [
{ "id" : "14031871223912313", ...}
...
]
I would like to query return the id's with Spring Data's MongoTemplate using the following:
class Chapter {
private String id;
public String getId() {
return id;
}
}
This way the id is not populated. I have tried using the different mapping options with #Field described here http://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#mapping.conventions.id-field
What am I doing wrong? I know I can always to back to mongo java driver, but I thought this should work.
Thanks in advance for any help.
Found a solution. It is populated via:
#Field("id")
private String chaperId
In MongoDB id's are _id, and every document in mongo has an _id. From the document you linked to, Spring will map #Field String id to mongo's _id field. You probably want to use a #Field('id') String id field mapping to indicate that the field you want is id not _id.

Nested query in mongodb using spring data

I am trying to use nested Mongodb query but it does not work.
It is similar to Spring data mongodb query for subdocument field
But suggestions mentioned there does not work.
Please find my documents below.
#Document
public class Ticket {
#Id
private String id;
#DBRef
#CascadeSave
private Customer customer;
// getters and setters
}
#Document
public class Customer {
#Id
private String id;
private String firstName;
// getters and setters
}
public interface TicketRepository extends MongoRepository<Ticket, String> {
public List<Ticket> findByCustomerFirstName(String firstName);
}
I tried both findByCustomerFirstName and findByCustomer_FirstName but it does not work. Any suggestions ?
These suggestions are right it should work...
Official docs explains it as you did it:http://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#repositories.query-methods.query-property-expressions
Property expressions can refer only to a direct property of the
managed entity, as shown in the preceding example. At query creation
time you already make sure that the parsed property is a property of
the managed domain class. However, you can also define constraints by
traversing nested properties. Assume a Person has an Address with a
ZipCode. In that case a method name of
List<Person> findByAddressZipCode(ZipCode zipCode);
creates the
property traversal x.address.zipCode
Just one thing, remove #Document from Customer and try it, Mongodb didn't support join queries (I'm not sure if now it does)... so you're document should be Ticket and it must have a embbebed document Customer as a inner object and not in a different document.

How can I query to find mongo entities whose list of sub-entities contain a field matching a string?

I have a collection of entities that look like this:
public class ClientEntity {
#Id
private String id;
#Indexed(unique = true)
private String clientId;
private String name;
#DBRef
private List<ClientMachineEntity> machines;
...
}
...where ClientMachineEntity looks like:
public class ClientMachineEntity {
#Id
private String id;
#Indexed(unique = true)
private String clientMachineId;
private String hostName;
...
}
I have a working search that finds ClientEntities by matching against "clientId" and "name":
public List<ClientEntity> searchByIdAndName(String id, String name) {
Criteria idCriteria = Criteria.where("clientId").regex(id, "i");
Criteria nameCriteria = Criteria.where("name").regex(name, "i");
Query query = new Query(new Criteria().orOperator(idCriteria, nameCriteria));
...
}
So my question is, how can I expand this search so that it also matches against "clientMachineId" in the list of sub-entities? I tried adding the following criteria:
Criteria machineCriteria = Criteria.where("machines.clientMachineId").regex(id, "i");
...but that doesn't work, presumably because machines is a LIST of entities, not just a single sub-entity.
UPDATE: It seems like what I'm looking for is the .elemMatch() functionality, but when I try that:
Criteria machineCriteria = Criteria.where("machines").elemMatch(Criteria.where("clientMachineId").regex(id, "i"));
...I get the following error:
org.springframework.data.mapping.model.MappingException: No mapping metadata found for class com.mongodb.BasicDBObject
You can't query by fields in subentities linked with DBRef. If ClientMachineEntity would be embedded in ClientMachine - then you could use dot notation or $elemMatch depending on needs.
In your particular example - couldn't field ClientMachineEntity.clientMachineId be saved as _id and used as a primary key? Then you could get the results you need - take a look at: How to query mongodb with DBRef
My suggestion for development with Spring Data MongoDB is - first learn how to (and if it's possible) do it in plain Javascript with MongoDB console, then learn how to do the same with Spring Data MongoDB.

how to create a classes from mogodb

Can someone give me an example of code for mapping with morphia and mongodb?
This is my class which contains database fields. I don't know how to
make the connection between morphia and mongodb.
import com.google.code.morphia.annotations.*;
//#Entity
//define the name of the collection where this entity will be stored
#Entity("tabes")
class MappingMorphia {
#Id
String id;
String FACILITY;
String HOST;
String MESSAGE;
String PID;
String PRIORITY;
String PROGRAM;
int SEQNUM;
String SOURCE;
String SOURCEIP;
String TAGS;
//getters and setters
}
There are examples aplenty at the morphia github site: https://github.com/mongodb/morphia/wiki
Mongodb doesn't understand about classes as is, or at least not the way you are thinking. There is, however, a module called mongoose that lets your model your objects. I think that will suit you.
Here's a link to mongoose's docs
http://mongoosejs.com/docs/documents.html

MongoDB: query by #DBRef

I have a class hierarchy designed for store user notifications:
#Document
public class Notification<T> {
#Id
private String id;
#DBRef
private T tag;
...
}
#Document
public class NotificationA extends Notification<WrappedA> {
}
#Document
public class NotificationB extends Notification<WrappedB> {
}
...
This is useful for returning polymorphic arrays, allowing me to store any kind of data in the "tag" field. The problem starts when the wrapped objects contains #DBRef fields:
#Document
public class WrappedA {
#Id
private String id;
#DBRef
private JetAnotherClass referenced;
...
}
Queries on the fields of "tag" works fine:
db.NotificationA.find( {"tag.$id": ObjectId("507b9902...32a")} )
But I need to query on the fields of JetAnotherClass (two levels of #DBRef fields). I've tried with dot notation and also with subobjects but it returns null:
Dot notation:
db.NotificationA.findOne( {"tag.$referenced.$id": ObjectId("508a7701...29f")} )
Subobjects:
db.NotificationA.findOne( {"tag.$referenced": { "_id": ObjectId("508a7701...29f") }} )
Any help?
Thanks in advance!
Since you look like you are only querying by _id I believe you can do:
db.NotificationA.findOne({"tag.$id": ObjectId("blah")});
However:
But I need to query on the fields of JetAnotherClass (two levels of #DBRef fields).
DBRefs are not JOINs, they are merely a self describing _id in the event that you do not know the linking collection it will create a helper object so you don't have to code this yourself on the client side.
You can find more on DBRefs here: http://docs.mongodb.org/manual/applications/database-references/
Basically you can query the sub fields within the DBRef from the same document, i.e.: DBRef.$_id but you cannot, server-side, resolve that DBRef and query on the resulting fields.