public static User getUserByLogin(String username, String password) throws ESellException
	{
		makeConnection();
    	PreparedStatement preparedStatement = null;
    	
        if(conn != null)
        {
            try {
            	//SQL Statement vorbereiten
                String sql = "SELECT * FROM users WHERE (username= ? AND password = ?)";
                preparedStatement = conn.prepareStatement(sql);
                preparedStatement.setString(1, username);
                preparedStatement.setString(2, password);
                
                //Statement absetzen
                ResultSet result = preparedStatement.executeQuery();
                
                //Objekt-Mapping
                if(result.next())
                {
                	return new User(result);
                }
                else
                	throw new ESellException(ESellException.ErrorCode.NO_ENTRY_ERR);
            } catch (SQLException e) {
                e.printStackTrace();
                throw new ESellException(ESellException.ErrorCode.DB_ERR);
            }
        }
        else
        	throw new ESellException(ESellException.ErrorCode.DB_ERR);
	
	}