How to get firebase data in inner node without the outer node name?

Issue

I want to read data from firebase, in the ref ("locations/{{someLocation}}/logs/{{someDevice}}") but I do not know if exists a correct form to do, because I need to use ".on" to hear constantly all the devices changes, the problem is that I need to read all devices in logs in all locations, but I do not want another information, I just need information in logs or in the specific device, I know that I could reach that invoking one callback ".on" for each device, but I want a cleaner form to make it and in the documentation, there is no help for this.

maybe I could invoke a method like that

firebase.database("locations/{eachLocation}/logs/{eachDevice}").ref().on...

because I do not want all the devices, the problem is that I do not know if there is a form to make it thank you.

Solution

It sounds like you've nested your data too much. The Firebase documentation has explicit sections on avoiding nesting data and flattening data structures with hints on how to prevent this.

At first glance you'll need at least two top-level lists: locations and locationLogs. Under each you have the same keys as you have now, but the logs are now under /locationLogs/$key instead of under /locations/$key/logs. With that change you can get the logs for a location without getting the other data for that location.

---

If you don't know the location key, but don't want to get the logs for all locations, it sounds like you've nested another level too deep. Firebase queries work on a flat list of nodes, and can't search across multiple levels of unknown keys. If you want to search across all logs across all locations, you will need to keep a flat list of all logs. You can then tie each log back to its location, by adding the location ID to each log.

So that might lead to a structure of:

logs: {
  "adjustableLight....1": {
    locationId: "DTZB35",
    date: 156...,"
    ...
  }
}

Answered By - Frank van Puffelen