how to update a value in firebase realtime database using Cloud Functions for Firebase

Question

I went though the firebase docs for updating a value in realtime database using Cloud Functions for Firebase, but am not able to understand.

My database structure is

Answer 1

You are trying to call update() on a DeltaSnapshot object. There is no such method on that type of object.

var eventSnapshot = event.data;
eventSnapshot.update({
    "isVerified": true
});

event.data is a DeltaSnapshot. If you want to change the data at the location of the change represented by this object. Use its ref property to get a hold of a Reference object:

var ref = event.data.ref;
ref.update({
    "isVerified": true
});

Also, if you are reading or writing the database in a function, you should always return a Promise that indicates when the change is complete:

return ref.update({
    "isVerified": true
});

I would recommend taking Frank's advice from the comments and study the existing sample code and documentation to better understand how Cloud Functions works.