Loopback 3 query by Property of a embedded model

Question

I'm using loopback 3 to build a backend with mongoDB. So i have 2 models: Object and Attachment. Object have a relation Embeds2Many to Attachment.

Objects look like that in mongoDB

[
    {
        "fieldA": "valueA1",
        "attachments": [
            {
                "id": 1,
                "url": "abc.com/image1"
            },
            {
                "id": 2,
                "url": "abc.com/image2"
            }
        ]
    },
    {
        "fieldA": "valueA2",
        "attachments": [
            {
                "id": 4,
                "url": "abc.com/image4"
            },
            {
                "id": 5,
                "url": "abc.com/image5"
            }
        ]
    }
]

The question is: how can i get Objects with attachments.id=4 over the RestAPI?

I have try with the where and include filter. But it didn't work. It look like, that this function is not implemented in loopback3, right?

Answer 1

I have found the solution. It only works on Mongodb, Cloudant and Memory database.

{
    "filter": {
        "where": {
            "attachments.id": 4
        }
    }
}