How To Retrieve The Data ? Firebase 3.0 Database

How can i retrieve all the childs from 'compresor_1' for example? Firebase database: 'CompresoresEstandar' : { 'Compresor_1' : { 'Marca' : 'SANDEN', 'Modelo' : '505/5H0

Solution 1:

You can create a model class of your Compresores Object if every node contains same children as I can see from your JSON file.

Here:

CompresoresEstandarUnit.class

public class CompresoresEstandarUnit {

    String Marca;
    String Modelo;
    String Canales;
    String Dimametro_MM; //Recommend you to change Firebase Node name to Dimametro_MM
    String Voltios;
    String Conextion;

    public CompresoresEstandarUnit() {
        //Firebase Empty Constructor
    }

    public String getCanales() {
        return Canales;
    }

    public void setCanales(String canales) {
        Canales = canales;
    }

    public String getConextion() {
        return Conextion;
    }

    public void setConextion(String conextion) {
        Conextion = conextion;
    }

    public String getDimametro_MM() {
        return Dimametro_MM;
    }

    public void setDimametro_MM(String dimametro_MM) {
        Dimametro_MM = dimametro_MM;
    }

    public String getMarca() {
        return Marca;
    }

    public void setMarca(String marca) {
        Marca = marca;
    }

    public String getModelo() {
        return Modelo;
    }

    public void setModelo(String modelo) {
        Modelo = modelo;
    }

    public String getVoltios() {
        return Voltios;
    }

    public void setVoltios(String voltios) {
        Voltios = voltios;
    }
}

And then in your listener:

@Override
public void onStart(){
    super.onStart();
    DatabaseReference mRootRef = FirebaseDatabase.getInstance().getReference();
    mRootRef.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
         dataSnapshot.getChildren();
            CompresoresEstandarUnit coe = dataSnapshot.getValue(CompresoresEstandarUnit.class);


            String modelo = coe.getModelo();
            mConditionTextView.setText(modelo);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });*/

This object oriented approach will provide flexibility to the structure.