DB upgrade example

db_helper.java

public class DatabaseHelper extends SQLiteOpenHelper {

    public static final String DATABASE_NAME = "utilities.db";
    private static final int DATABASE_VERSION = 3;

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(Tables.Counters.CREATE);
        db.execSQL(Tables.Records.CREATE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (oldVersion < 3) {
            Calendar calendar = Calendar.getInstance();

            db.beginTransaction();
            try {
                String tempRecordsName = Tables.Records.NAME + "_temp";
                db.execSQL("ALTER TABLE " + Tables.Records.NAME + " RENAME TO " + tempRecordsName);
                db.execSQL(Tables.Records.CREATE);

                Cursor cursor = db.query(tempRecordsName, null, null, null, null, null, null);
                if (cursor != null) {
                    while (cursor.moveToNext()) {
                        int counterId = cursor.getInt(Tables.Records.INDEX_COUNTER_ID);
                        double value = cursor.getDouble(Tables.Records.INDEX_VALUE);
                        long date = cursor.getLong(Tables.Records.INDEX_DATE);
                        calendar.setTimeInMillis(date);
                        int month = calendar.get(Calendar.MONTH);
                        int year = calendar.get(Calendar.YEAR);

                        ContentValues values = new ContentValues(5);
                        values.put(Tables.Records.COLUMN_COUNTER_ID, counterId);
                        values.put(Tables.Records.COLUMN_VALUE, value);
                        values.put(Tables.Records.COLUMN_DATE, date);
                        values.put(Tables.Records.COLUMN_DATE_MONTH, month);
                        values.put(Tables.Records.COLUMN_DATE_YEAR, year);

                        db.insert(Tables.Records.NAME, null, values);
                    }

                    cursor.close();
                }

                db.execSQL(Tables.DROP + tempRecordsName);
                db.setTransactionSuccessful();
            } finally {
                db.endTransaction();
            }
        }
        if (oldVersion < 2) {
            db.execSQL("ALTER TABLE " + Tables.Counters.NAME + " ADD COLUMN " + Tables.Counters.COLUMN_SOURCE + " TEXT DEFAULT NULL");
        }
    }
}