Query MongoDB with morphia by element on String list

Question

This is the documents format:

{
 "_id" : ObjectId("123")
 "types" : [ "PHONE", "ADDRESS" ]
},
{
 "_id" : ObjectId("345")
 "types" : [ "PHONE" ]
},
{
 "_id" : ObjectId("567")
 "types" : [ "PHONE", "NAME" ]
}

And this is the query to find elements which contains certain types:

public List<MyCollection> findByType(Type type) {
  return getDatastore().createQuery(MyCollection.class)
     .field("types").hasThisElement(type.toString())
     .asList();
}

With this code, I get this error:

com.mongodb.MongoException: Can't canonicalize query: BadValue $elemMatch needs an Object

I tried using hasThisOne method, but always returns an empty array.

How can I do this query?

Answer 1

Why are you using a type.toString()?

I'd assume you have a List<Type> types in your entity, right? Then the query should use the enum as well and not its string representation.

And you can probably use:

getDatastore().createQuery(MyCollection.class)
   .field("types").equal(type).asList();

Yes, even for arrays.