Db2

public void viewAll() {
        btnviewAll.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                       Cursor res = myDb.getAllData();
                        if(res.getCount() == 0) {
                            // show message
                            showMessage("Error","Nothing found");
                            return;
                        }

                        StringBuffer buffer = new StringBuffer();
                        while (res.moveToNext()) {
                            buffer.append("Id :"+ res.getString(0)+"\n");
                            buffer.append("Name :"+ res.getString(1)+"\n");
                            buffer.append("Surname :"+ res.getString(2)+"\n");
                            buffer.append("Marks :"+ res.getString(3)+"\n\n");
                        }

                        // Show all data
                        showMessage("Data",buffer.toString());
                    }
                }
        );
    }
//////////////////////////////////
 public  void AddData() {
        btnAddData.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                       boolean isInserted = myDb.insertData(editName.getText().toString(),
                                editSurname.getText().toString(),
                                editMarks.getText().toString() );
                        if(isInserted == true)
                            Toast.makeText(MainActivity.this,"Data Inserted",Toast.LENGTH_LONG).show();
                        else
                            Toast.makeText(MainActivity.this,"Data not Inserted",Toast.LENGTH_LONG).show();
                    }
                }
        );
    }

/////////////////////////////
   boolean isInserted = myDb.insertData(editName.getText().toString(),
                                editSurname.getText().toString(),
                                editMarks.getText().toString() );
                        if(isInserted == true)
                            Toast.makeText(MainActivity.this,"Data Inserted",Toast.LENGTH_LONG).show();
                        else
                            Toast.makeText(MainActivity.this,"Data not Inserted",Toast.LENGTH_LONG).show()
/////////////////////////////////////
Cursor res = myDb.getAllData();
                        if(res.getCount() == 0) {
                            // show message
                            showMessage("Error","Nothing found");
                            return;
                        }

                        StringBuffer buffer = new StringBuffer();
                        while (res.moveToNext()) {
                            buffer.append("Id :"+ res.getString(0)+"\n");
                            buffer.append("Name :"+ res.getString(1)+"\n");
                            buffer.append("Surname :"+ res.getString(2)+"\n");
                            buffer.append("Marks :"+ res.getString(3)+"\n\n");
                        }

                        // Show all data
                        showMessage("Data",buffer.toString());
////////////////////////////////////////////////
public class DatabaseHelper extends SQLiteOpenHelper {
    public static final String DATABASE_NAME = "Student.db";
    public static final String TABLE_NAME = "student_table";
    public static final String COL_1 = "ID";
    public static final String COL_2 = "NAME";
    public static final String COL_3 = "SURNAME";
    public static final String COL_4 = "MARKS";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table " + TABLE_NAME +" (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,SURNAME TEXT,MARKS INTEGER)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
        onCreate(db);
    }

    public boolean insertData(String name,String surname,String marks) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_2,name);
        contentValues.put(COL_3,surname);
        contentValues.put(COL_4,marks);
        long result = db.insert(TABLE_NAME,null ,contentValues);
        if(result == -1)
            return false;
        else
            return true;
    }

    public Cursor getAllData() {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res = db.rawQuery("select * from "+TABLE_NAME,null);
        return res;
    }

    public boolean updateData(String id,String name,String surname,String marks) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_1,id);
        contentValues.put(COL_2,name);
        contentValues.put(COL_3,surname);
        contentValues.put(COL_4,marks);
        db.update(TABLE_NAME, contentValues, "ID = ?",new String[] { id });
        return true;
    }

    public Integer deleteData (String id) {
        SQLiteDatabase db = this.getWritableDatabase();
        return db.delete(TABLE_NAME, "ID = ?",new String[] {id});
    }
}
////////////////////////////////////////