当我尝试从 firebase 更新数据时出错

Question

i want to update some data from firebase using my app, but when i submit it, the data only gets duplicated, not changed, and don't know why. I put my code below:

My class userPojo

 package com.example.proyectofinaldanielsanchez;

import java.io.Serializable;

public class userPojo implements Serializable {

private String Tipo;
private String Titulo;
private String Avance;
private String Plataforma;
private String Key;

public userPojo() {

}
public userPojo(String Tipo, String Titulo, String Avance, String Plataforma){
    this.Tipo=Tipo;
    this.Titulo=Titulo;
    this.Avance=Avance;
    this.Plataforma=Plataforma;
}

public String getTipo() {
    return Tipo;
}

public void setTipo(String Tipo) {
    this.Tipo = Tipo;
}

public String getKey() {
    return Key;
}

public void setKey(String Key) {
    this.Key = Key;
}

public String getTitulo() {

    return Titulo;
}

public void setTitulo(String Titulo) {
    this.Titulo = Titulo;
}

public String getAvance() {
    return Avance;
}

public void setAvance (String Avance) {
    this.Avance = Avance;
}



public String getPlataforma() {
    return Plataforma;
}

public void setPlataforma(String Plataforma) {
    this.Plataforma = Plataforma;
}

}

Class Adapter:

 package com.hellokh.sovary.firetest;

  import android.content.Context; 
  import android.content.Intent;
   import android.view.LayoutInflater;
    import android.view.View;
   import android.view.ViewGroup;
 import android.widget.PopupMenu;
 import android.widget.Toast;

  import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;

  import java.util.ArrayList;

  public class RVAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>
{
private Context context;
ArrayList<Employee> list = new ArrayList<>();
public RVAdapter(Context ctx)
{
    this.context = ctx;
}
public void setItems(ArrayList<Employee> emp)
{
    list.addAll(emp);
}

@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)
{
    View view = LayoutInflater.from(context).inflate(R.layout.layout_item,parent,false);
    return new EmployeeVH(view);
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position)
{
    Employee e = null;
    this.onBindViewHolder(holder,position,e);
}

public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position, Employee e)
{
    EmployeeVH vh = (EmployeeVH) holder;
    Employee emp = e==null? list.get(position):e;
    vh.txt_name.setText(emp.getName());
    vh.txt_position.setText(emp.getPosition());
    vh.txt_option.setOnClickListener(v->
    {
        PopupMenu popupMenu =new PopupMenu(context,vh.txt_option);
        popupMenu.inflate(R.menu.option_menu);
        popupMenu.setOnMenuItemClickListener(item->
        {
            switch (item.getItemId())
            {
                case R.id.menu_edit:
                    Intent intent=new Intent(context,MainActivity.class);
                    intent.putExtra("EDIT",emp);
                    context.startActivity(intent);
                    break;
                case R.id.menu_remove:
                    DAOEmployee dao=new DAOEmployee();
                    dao.remove(emp.getKey()).addOnSuccessListener(suc->
                    {
                        Toast.makeText(context, "Record is removed", Toast.LENGTH_SHORT).show();
                        notifyItemRemoved(position);
                        list.remove(emp);
                    }).addOnFailureListener(er->
                    {
                        Toast.makeText(context, ""+er.getMessage(), Toast.LENGTH_SHORT).show();
                    });

                    break;
            }
            return false;
        });
        popupMenu.show();
    });
}

@Override
public int getItemCount()
{
    return list.size();
}
}

Class Archivos:

   package com.example.proyectofinaldanielsanchez;


import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.HashMap;
import java.util.Map;

public class Archivos extends AppCompatActivity  {


protected void onCreate(Bundle savedInstanceState)
{
    
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_archivos2);
    final EditText edit_tipo = findViewById(R.id.edit_tipo);
    final EditText edit_titulo = findViewById(R.id.edit_titulo);
    final EditText edit_avance=findViewById(R.id.edit_avance);
    final EditText edit_plataforma=findViewById(R.id.edit_plataforma);
    Button btn = findViewById(R.id.btn_submit);
    Button btn_open = findViewById(R.id.btn_open);
    btn_open.setOnClickListener(v->
    {
        Intent intent =new Intent(Archivos.this, Visualizar.class);
        startActivity(intent);
    });
    DAOUserPojo dao =new DAOUserPojo();
    userPojo user_edit = (userPojo) getIntent().getSerializableExtra("EDIT");
    if(user_edit !=null)
    {
        btn.setText("UPDATE");
        edit_tipo.setText(user_edit.getTipo());
        edit_titulo.setText(user_edit.getTitulo());
        edit_avance.setText(user_edit.getAvance());
        edit_plataforma.setText(user_edit.getPlataforma());

        btn_open.setVisibility(View.GONE);
    }
    else
    {
        btn.setText("SUBMIT");
        btn_open.setVisibility(View.VISIBLE);
    }
    btn.setOnClickListener(v->
    {
        userPojo user = new userPojo(edit_tipo.getText().toString(), edit_titulo.getText().toString(),edit_avance.getText().toString(),edit_plataforma.getText().toString());
        if(user_edit==null)
        {
            dao.add(user).addOnSuccessListener(suc ->
            {
                Toast.makeText(this, "Record is inserted", Toast.LENGTH_SHORT).show();
            }).addOnFailureListener(er ->
            {
                Toast.makeText(this, "" + er.getMessage(), Toast.LENGTH_SHORT).show();
            });
        }
        else
        {
          
            HashMap<String, Object> hashMap = new HashMap<>();
            hashMap.put("tipo", edit_tipo.getText().toString());
            hashMap.put("titulo", edit_titulo.getText().toString());
            hashMap.put("avance", edit_avance.getText().toString());
            hashMap.put("plataforma", edit_plataforma.getText().toString());
            dao.update(user_edit.getKey(), hashMap).addOnSuccessListener(suc ->
            {
                Toast.makeText(this, "Record is updated", Toast.LENGTH_SHORT).show();
                finish();
            }).addOnFailureListener(er ->
            {
                Toast.makeText(this, "" + er.getMessage(), Toast.LENGTH_SHORT).show();
            });
        }
    });


}
    }

class DAOUserPojo

     public class DAOUserPojo {

private DatabaseReference databaseReference;
private FirebaseAuth userid;

public DAOUserPojo() {
    FirebaseDatabase db =FirebaseDatabase.getInstance("https://proyecto-daniel-sanchez-default-rtdb.europe-west1.firebasedatabase.app");
    databaseReference = db.getReference();
    userid = FirebaseAuth.getInstance();


   // userid=FirebaseAuth.getInstance().getCurrentUser();
}
public Task<Void> add(userPojo user)
{
    return databaseReference.child(userid.getUid()).push().setValue(user);
}

public Task<Void> update(String Key, HashMap<String ,Object> hashMap)
{
    return databaseReference.child(userid.getUid()).child(Key).updateChildren(hashMap);
}
public Task<Void> remove(String Key)
{
    return databaseReference.child(userid.getUid()).child(Key).removeValue();
}

public Query get(String Key)
{
    if(Key == null)
    {
        return databaseReference.child(userid.getUid()).orderByKey().limitToFirst(8);
    }
    return databaseReference.child(userid.getUid()).orderByKey().startAfter(Key).limitToFirst(8);
}

public Query get()
{
    return databaseReference;
}
}

And this is the nodes of my database when i try to update. It should be like first node, but it get duplicate: firebase Sry for my bad english. If someone can help, would be amazing, Thanks!

Answer 1

let's start with uploading New:

I would suggest adding aditional child lets name is id for example and the value of this child would be same as the value of firebase push id.

let's get with Editing:

pass a (String) textId variable for adapter so that when you click on edit from the menu it would set the textId value to be the push id from the firebase, which would be the child that have data you need to edit.

now use the child(textId).updateChildren(//Your hashmap);

and it would work.

Example of my usage:

String textId= productRef.child(UID).child("images").push().getKey();


HashMap<String ,Object> hashMap = new HashMap<>();
        hashMap.put("image", url);
        hashMap.put("id", textId);

 productRef.child(UID).child("images").child(textId).updateChildren(hashMap);

It would look like this:

have you notice the id is the same as the Child Name