private static final String TABLE_STUDENTS="CREATE TABLE STUDENTS(NAMES TEXT,
                                           LASTNAME TEXT, ID TEXT, IMAGE IMAGEVIEW)";

//...Class constructor and methods OnCreate and onUpgrade

public void addStudents(String names, String lastname , String id, int img){
    SQLiteDatabase bd = getWritableDatabase();
    if(bd != null){
        bd.execSQL("INSERT INTO STUDENTS VALUES('"+names+"','"+lastname+"','"+id+"','"+
        img+"')");
        bd.close();
    }
}

public List<Student> showStudents(){
    /*Student is the class where I defined the general attributes*/
    SQLiteDatabase bd = getReadableDatabase();
    final Cursor cursor = bd.rawQuery("SELECT * FROM STUDENTS",null);
    final List<Student> students = new ArrayList<>();
    if(cursor.moveToFirst()){
        do{
            students.add(new Student(cursor.getString(0),cursor.getString(1),
            cursor.getString(2), cursor.getInt(3)));
        }while (cursor.moveToNext());
    }
    return students;
}

private RecyclerView recyclerViewStudents;
private AdapterStudentsLists adapterStudentsList;

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

    recyclerViewStudents = (RecyclerView) findViewById(R.id.recyclerStudents);
    recyclerViewStuents.setLayoutManager(new LinearLayoutManager(this));

    final SQLiteDb sqLiteDb = new SQLiteDb(getApplicationContext());
    recyclerViewStudents.setAdapter(adapterStudentsList);

    adapterStudentsList = new AdapterStudentsList(sqLiteDb.showStudents());
    adapterStudentsList.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Toast.makeText(getApplicationContext(),"Id: "/*+ SELECTED STUDENT ID */,
            Toast.LENGTH_SHORT).show();
        }
    });
    recyclerViewStudents.setAdapter(adapterStudentsList);
}

public static  class  ViewHolder extends RecyclerView.ViewHolder{
       private TextView CompleteName;
       ImageView ImageStudent;
    public ViewHolder(View itemView) {
        super(itemView);
        NombreCompleto =(TextView)itemView.findViewById(R.id.tvNombreCompleto);
        ImagenAlumno = (ImageView)itemView.findViewById(R.id.imgAlumno);
    }
}

public List<Alumno> alumnosLista;

public AdatadorListaAlumnos(List<Alumno>alumnosLista){
    this.alumnosLista = alumnosLista;
}

@Override
public void onBindViewHolder (ViewHolder holder, final int position) {
    holder.NombreCompleto.setText(alumnosLista.get(position).getNombres() + " " +
      alumnosLista.get(position).getApellidos());
holder.ImagenAlumno.setImageResource(alumnosLista.get(position).getImagen());
}

private View.OnClickListener listener;

public void setOnClickListener(View.OnClickListener listener){
    this.listener=listener;
}

@Override
public void onClick(View view) {
    if(listener!=null) {
        listener.onClick(view);
    }
}