javascript - Check if value exists in firebase DB

Question

Is there a method in firebase, which can check if value exist in DB? Firebase has method .exists(), but according to docs it checks only the keys.

I have the following structure:

{
  "users": {
    "-KKUmYgLYREWCnWeHCvO": {
      "fName": "Peter",
      "ID": "U1EL9SSUQ",
      "username": "peter01"
    },
    "-KKUmYgLYREWCnWeHCvO": {
      "fName": "John",
      "ID": "U1EL5623",
      "username": "john.doe"
    }
  }
}

I want to check if ID with value U1EL5623exists.

Answer 1

Waitting for answers