public class DatabaseHelper extends SQLiteOpenHelper {

    private Context dbContext;

    private static String DB_NAME = "appData.db";
    private String DB_PATH = "";

    private static final int DB_VERSION = 1;

    private SQLiteDatabase mDatabase;


    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        this.dbContext = context;
        DB_PATH = dbContext.getApplicationInfo().dataDir + "/databases/";

        if (checkDataBase()) {
            Log.d("database_test", "Open database call");
            openDataBase();
        } else {
            try {
                Log.d("database_test", "Open database not call");
                this.getReadableDatabase();
                Log.d("database_test", "copy database call");
                copyDataBase();
                this.close();
                openDataBase();

            } catch (IOException e) {
                throw new Error("Error copying database");
            }
            Toast.makeText(context, "Initial database is created", Toast.LENGTH_LONG).show();
        }

    }


    private void copyDataBase() throws IOException {
        Log.d("database_test", "Copy database call 2");
        InputStream myInput = dbContext.getAssets().open(DB_NAME);
        String outFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outFileName);

        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }

        myOutput.flush();
        myOutput.close();
        myInput.close();
        Log.d("database_test", "Open database worked finish");
    }

    public void openDataBase() throws SQLException {
        Log.d("database_test", "Open database call 2");
        String dbPath = DB_PATH + DB_NAME;
        mDatabase = SQLiteDatabase.openDatabase(dbPath, null, SQLiteDatabase.OPEN_READWRITE);
    }


    private boolean checkDataBase() {
        SQLiteDatabase checkDB = null;
        boolean exist = false;
        try {
            String dbPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(dbPath, null,
                    SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {
            Log.v("db_log", "database does't exist");
        }

        if (checkDB != null) {
            exist = true;
            checkDB.close();
        }
        return exist;
    }

    public void getAllTableName() {
        mDatabase = getReadableDatabase();
        Cursor c = mDatabase.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);

        if (c.moveToFirst()) {
            while (!c.isAfterLast()) {
                Log.d("db_test", "table list: " + c.getString(0));
                // Toast.makeText(acti, "Table Name=> "+c.getString(0), Toast.LENGTH_LONG).show();
                c.moveToNext();
            }
        }
        c.close();
    }

    public Cursor getTestData() {
        Cursor cursor = mDatabase.rawQuery("SELECT * FROM qna", null);
        /*if (cursor != null) {
            while (cursor.moveToNext()) {

                String value = cursor.getString(1);
                Log.d("db_test", "table value: " + value);
            }
           // cursor.close();
        }*/

        return cursor;
    }




    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }


}