Query MongoDb collection regarding an array of objects in a Go project

In a Go project I stored some data like this in a MongoDb Collection:

{
    _id:ObjectId("631f0752da589137a71687f6"),
    target: { roomId: '11' }
}

{
    _id:ObjectId("43150752da589137a71687f6"),
    target: { roomId: '12' }
}
.
.
.

I have a target array of objects and I want to check the database that if a roomId in database is equal to one of my array of objects values or not.

My target array of objects:

 userRooms:[{"roomId":"12"}, {"roomId":"13"}, {"roomId":"14"}]
 

I create a new array containing just room Id’s like this:

var roomIds []string
for _, v := range RESPONSE.USERROOMS {
    roomIds = append(roomIds, v.ROOMID)
}

I do it like this:

bson.M{ "target": bson.M{"roomId":bson.M{"$in": roomIds }}}}}})

It doesn’t work. it returns zero results.

>Solution :

To construct a filter for a nested field, use the dot . to designate the field with its full "path":

bson.M{"target.roomId": bson.M{"$in": roomIds}}

Where roomIds should be the slice of IDs, e.g. of type []string or []any, but it should contain the room IDs as strings.