没有从Android中的Firebase获取子数据

Question

Here is the following structure of database in firebase

Code

I am getting the current user and then checking the whether the id is null or not and get reference of child and getting key of child. Further more i am getting null in string variable where i tried to get values.

private void Check_data() {
    final FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
    if (user.getUid() != null) {
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        DatabaseReference myRef = database.getReference("user_info");
        DatabaseReference myRef1=myRef.child(user.getUid());
        myRef1.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                //GenericTypeIndicator<Map<String, String>> genericTypeIndicator = new GenericTypeIndicator<Map<String, String>>() {};
                   // Map<String, String> map = dataSnapshot.getValue(genericTypeIndicator);
                    String name = dataSnapshot.child("name").getValue(String.class);
                    String email = dataSnapshot.child("email").getValue(String.class);


                        Name.setText(name);
                        email_txt.setText(email);


               /* if (image != null) {
                    Glide.with(MainActivity.this)
                            .load(image)
                            .centerCrop()
                            .into(photo_url);

                }*/

                }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

    }
}

Answer 1

In your database, you have random ids that are generated using push()

You should first when adding data to the database use the userid :

FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();
String userid=user.getUid();

the userid is unique for each user.

then to retrieve the data inside the userid :

 DatabaseReference myRef = database.getReference("user_info");
 DatabaseReference myRef1=myRef.child(userid);
 myRef1.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
                String name = dataSnapshot.child("name").getValue(String.class);
                String email = dataSnapshot.child("email").getValue(String.class)
  }
});

When the id has - at the beginning it means its a random id.