دیتابیس سینگل تون - 2

کلاس سینگل تون DBHelper که توش از کلاس SQLiteOpenHelper نیو میکنیم.

 

public class DBHelper {

    private static DBHelper dBHelperInstance;
    private CreateTable createTable;
    private SQLiteDatabase database;
    private int count = 0;

    public static synchronized void init(Context context) {

        if (dBHelperInstance == null) {

            dBHelperInstance = new DBHelper(context);
        }
    }

    private DBHelper(Context context) {

        createTable = new CreateTable(context);
    }

    public static synchronized DBHelper getInstance() {

        if (dBHelperInstance == null) {
            throw new IllegalStateException(DBHelper.class.getSimpleName() +
                    " is not initialized, call init(..) method first.");
        }

        return dBHelperInstance;
    }

    public synchronized void openDatabase() {

        count++;
        if (count == 1) {
            database = createTable.getWritableDatabase();

        }

    }

    public synchronized void closeDatabese() {

        count--;
        if (count == 0) {

            createTable.close();
        }

    }

متد insert

 

 

متد select

 

 

متد update

 

 

متد delete