实时数据库未更新 // Firebase Kotlin 中的数据未更新

Question

This is the problem:

These are the rules I set in Firebase:

The Current users in Firebase:

When I make a new user, It should be updated in Firebase Realtime DB. But in this case, this does not help. I even changed the read, write rules to true, it doesn't help & keeps showing null.

//CODE BELOW//

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_sign_up)
    supportActionBar?.hide()

    mAuth = FirebaseAuth.getInstance()
    edtName =findViewById(R.id.edt_name)
    edtEmail =findViewById(R.id.edt_email)
    edtPassword =findViewById(R.id.edt_password)
    btnSignUp =findViewById(R.id.btn_signup)

    btnSignUp.setOnClickListener{
        val name = edtName.text.toString()
        val email = edtEmail.text.toString()
        val password = edtPassword.text.toString()

        signUp(name, email,password)

    }
}
private fun signUp(name:String, email: String,password: String){
    //logic for signup

    mAuth.createUserWithEmailAndPassword(email, password)
        .addOnCompleteListener(this) { task ->
            if (task.isSuccessful) {
                //going homE
                addUserToDatabase(name, email, mAuth.currentUser?.uid!!)

                val intent= Intent(this@SignUp, MainActivity::class.java)
                startActivity(intent)

            } else {
                Toast.makeText(this@SignUp, "Some Error occurred", Toast.LENGTH_SHORT).show()

            }
        }

}
private fun addUserToDatabase(name:String, email:String, uid:String){
    mDbRef=FirebaseDatabase.getInstance().getReference()

    mDbRef.child("user").child(uid).setValue(User(name, email, uid))

}

}

//User Class Code//

package com.example.mychat

class User {
   var name : String? = null
   var email : String? = null
   var uid : String? = null

   constructor(){}

   constructor(name:String?, email:String?, uid:String?){
     this.name= name
     this.email=email
     this.uid=uid
   }


 }

Answer 1

Check data is successfully saved to the database or not

In your addUserToDatabase function add this code to check the status

mDbRef.child("user").child(uid).setValue(User(name, email, uid)).addOnCompleteListener(new OnCompleteListener<Void>() {
            @Override
            public void onComplete(@NonNull Task<Void> task) {
                if (task.isSuccessful()){
                    Toast.makeText(this, "Data Added Successfully", Toast.LENGTH_SHORT).show();
                } else { 
                    Toast.makeText(this, task.getException().getMessage(), Toast.LENGTH_SHORT).show();
                    Log.d(TAG, task.getException().getMessage());
                }
            }
        });

Answer 2

If you're getting neither a completion nor an error listener, did you download your google-services.json before you first accessed the database in the console by any chance? In that case, the file might not contain the database reference that the SDK needs. To fix this, download a new google-service.json from your project and use that in your app, or specify the database URL in your code in mDbRef=FirebaseDatabase.getInstance("URL here").getReference().

This Solution by @Frank van Puffelen worked.