Firebase: What's the correct way to update values?

Question

If my database structure is like this:

and I have this:

    ref = Database.database().reference().child(passUserID)

    ref?.child("wins").updateChildValues("wins": numerator)

where numerator = (games played beforehand) + (games played after logging in), for the second statement it is giving me an error in the expression that I don't know how to fix.

Also if I try to do this instead:

ref?.child("wins").setValue(numerator)

it messes up my data bad and gives a bad instruction error.

score 1 · Answer 1 · answered Jun 04 '17 at 17:19

The updateChildValues method takes a Dictionary. So you just need to call the method with a dictionary containing the key-value pairs you want to update, i.e.

ref = Database.database().reference().child(passUserID)

ref?.updateChildValues(["wins": numerator])

For more on how to read/write data to firebase realtime database, refer to: https://firebase.google.com/docs/database/ios/read-and-write

score 0 · Answer 2 · answered Jun 04 '17 at 16:31

If you use .setValue triggers only in the beginning. Instead of .setValue use updateChildValues(.values/.childAdded/.childRemoved etc..) to update the values inside your tree. It will be executed whenever changes occurs to your node.

How to update particular value of child in Firebase DB

Firebase: What's the correct way to update values?

2 Answers2