public List<String> getDataList(String sql){
		List<String> list = new ArrayList<String>();
		this.conn = connectToDB();
		if(this.conn != null){
			ResultSet rs = null;
			try {
				PreparedStatement pstmt = this.conn.prepareStatement(sql);
				rs = pstmt.executeQuery();
				while(rs.next()){
					list.add(rs.getString(1));
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}			
		}
		if(this.conn != null){
			closeConnection();
		}
		return list;
	}