单击单选按钮后如何更新Firebase中的数据？

Question

I am designing a ticket app to get ticket. Every restaurant contain the ticket number of three party size. Radio buttons are the choices.

I try to update the Firebase.

Hope to change QueueA "0" to 1 if the user has clicked the btnPartSize1_2

Yet, it can't. I am wondering there is some problem in codes and I am trying to modify the btnPartySize button part so that I need not duplicate the same codes in three times.

Please help.

The image show the data structure in Firebase

public class Queue extends AppCompatActivity {

    RadioGroup radioGroup;
    RadioButton btnPartySize1_2, btnPartySize3_4, btnPartySize5_6;
    Button buttonQueue;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_queue);

        buttonQueue = (Button) findViewById(R.id.btnQueue);
        btnPartySize1_2 = (RadioButton) findViewById(R.id.btnPartySize1_2);
        btnPartySize3_4 = (RadioButton) findViewById(R.id.btnPartySize3_4);
        btnPartySize5_6 = (RadioButton) findViewById(R.id.btnPartySize5_6);
        final RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioGroup);

        FirebaseDatabase database = FirebaseDatabase.getInstance();
        final DatabaseReference table_user = database.getReference("Restaurant");
        final DatabaseReference QueueA = FirebaseDatabase.getInstance().getReference("QueueA");
        final DatabaseReference QueueB = FirebaseDatabase.getInstance().getReference("QueueB");
        final DatabaseReference QueueC = FirebaseDatabase.getInstance().getReference("QueueC");

        buttonQueue.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
              if(btnPartySize1_2.isChecked()) {

                            ValueEventListener eventListener = new ValueEventListener() {
                                @Override
                                public void onDataChange(DataSnapshot dataSnapshot) {
                                    int QueueA = dataSnapshot.child("QueueA").getValue(Integer.class);
                                    QueueA++;
                                    this.child("QueueA").setValue(QueueA);
                                    Toast.makeText(Queue.this, "You have collected", Toast.LENGTH_SHORT).show();
                                }

                                @Override
                                public void onCancelled(DatabaseError databaseError) {

                                }
                            };
                            QueueA.addListenerForSingleValueEvent(eventListener);
                        } else if (btnPartySize3_4.isChecked()) {


                            ValueEventListener eventListener = new ValueEventListener() {
                                @Override
                                public void onDataChange(DataSnapshot dataSnapshot) {
                                    int counter = dataSnapshot.child("counter").getValue(Integer.class);
                                    counter++;
                                    QueueB.child("counter").setValue(counter);
                                    Toast.makeText(Queue.this, "You have collected", Toast.LENGTH_SHORT).show();
                                }

                                @Override
                                public void onCancelled(DatabaseError databaseError) {

                                }
                            };
                            QueueB.addListenerForSingleValueEvent(eventListener);

                        } else if (btnPartySize5_6.isChecked()) {


                            ValueEventListener eventListener = new ValueEventListener() {
                                @Override
                                public void onDataChange(DataSnapshot dataSnapshot) {
                                    int counter = dataSnapshot.child("counter").getValue(Integer.class);
                                    counter++;
                                    QueueC.child("counter").setValue(counter);
                                    Toast.makeText(Queue.this, "You have collected", Toast.LENGTH_SHORT).show();
                                }

                                @Override
                                public void onCancelled(DatabaseError databaseError) {

                                }
                            };
                            QueueC.addListenerForSingleValueEvent(eventListener);

                        } else {

                            Toast.makeText(Queue.this, "Please choose party size", Toast.LENGTH_SHORT).show();
                        }


            }
        });

}

Can anyone help? Want your help sincerely!!

Answer 1

To make it simpler, change the logic of your code. Create a single ValueEventListener object and inside onDataChange() method add the logic about your radio buttons.

if(btnPartySize1_2.isChecked()) {
    int QueueA = dataSnapshot.child("QueueA").getValue(Integer.class);
    QueueA++;
    this.child("QueueA").setValue(QueueA);
} else if () {
    int counter = dataSnapshot.child("counter").getValue(Integer.class);
    counter++;
    QueueB.child("counter").setValue(counter);
}
// and so on.

Answer 2

You need to change the reference since it is wrong:

Currently this is your reference:

 FirebaseDatabase database = FirebaseDatabase.getInstance();
    final DatabaseReference table_user = database.getReference("Restaurant");
    final DatabaseReference QueueA = FirebaseDatabase.getInstance().getReference("QueueA");
    final DatabaseReference QueueB = FirebaseDatabase.getInstance().getReference("QueueB");
    final DatabaseReference QueueC = FirebaseDatabase.getInstance().getReference("QueueC");

Now you have:

 rootnode
     Category
     Restaurant
         01
           Key:value
           key:value //one of those is QueueA

So try this:

       FirebaseDatabase database = FirebaseDatabase.getInstance();
       final DatabaseReference ref=database.getReference().child("Restaurant").child("01").child("QueueA");

You have to go by order from top to bottom or the reference will be wrong.