How to validate and seperate set value

Hi everyone, I have a little bit of trouble with validating a value and separating set value.
I created an app that lets you see the tasks that you need to do, very simple. Now I created a realtime database for it so if I would lose the app it retrieves all the data that is stored under my name. Everything works from deleting data to save data, the only thing that I’m struggling with is getting set data to check if there is an item on the storage that isn’t in the list. If there is, I want the storage to update the list/create a new row on the local data source.
What I think I need to do is set the value that the Real-TimeDB gets in a JSON format, then compare that value with the row “RowID” (I’ve created a row that stores the rowID cause it’s simpler to work with). At least that’s what I think, I don’t really know what blocks I would need to use for that.

Hey @jens12341234 - did you ever manage to get this working?

Mind sharing a screenshot of the blocks you’re using to do this at the moment?