json-api how to set the special relationships data with ember data?

My /api/orders.json api look like:

{
    "data": {
        "id": "46636",
        "type": "order",
        "attributes": {
            "number": "12",
            "category": "out"
        },
        "relationships": {
            "lists": {
                "data": [
                    {
                        "id": "443",
                        "type": "lists"
                    }
                ]
            }
        }
    }
}

And they will find list from /api/lists/443:

{
    "data": {
        "id": "443",
        "type": "list",
        "attributes": {
            "number": "1",
            "category": "black"
        }
    }
}

There are everything is good. But my case is in the example above, my list is the sum of the need, not every one of the list. Just like:

{
    "data": {
        "id": "1",
        "type": "list",
        "attributes": {
            "number": "1",
            "category": "black"
        }
    }
}

{
    "data": {
        "id": "2",
        "type": "list",
        "attributes": {
            "number": "1",
            "category": "black"
        }
    }
}

{
    "data": {
        "id": "2",
        "type": "list",
        "attributes": {
            "number": "1",
            "category": "red"
        }
    }
}

Modified into(User sum, group and select SQL):

{
    "data": {
        "id": "xx",
        "type": "list",
        "attributes": {
            "number": "2",
            "category": "black"
        }
    }
}

{
    "data": {
        "id": "xx",
        "type": "list",
        "attributes": {
            "number": "1",
            "category": "red"
        }
    }
}

The problem is if I use group data's id is null and can not find the data. Because relatationships' data must find by id.

How do I solve this problem? I find a way to solve is use javascript like: http://ift.tt/1f0jdd4 . I think it will have another better to solve this problem. Thinks.