How to check if username already exists in firebase Realtime Database-CodePudding

I am trying to check were the users already exists with the same username here is example

Here is my code,

 DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
 Query checkUser = reference.orderByChild("userName").equalTo(userEnteredUserName);

but without the uid it works perfect, but whenever there is uid unable to check the username, Is there is anyway to check username

CodePudding user response：

The query is expecting userName to be a direct field in username node and because userId is not same for everyone you cannot specify a neste path. If you remove the username node and restructure the DB as shown below, the same query should work perfectly:

Users
  | // remove [username] node from here
  |-userId  // userId from Firebase Auth
    |
    |-userName
    |-otherFields

If you want to retain existing structure then you can just check if a node with given username exists:

DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users").child("userName");