public boolean isPhenomenonInDatabase(String phenomenon_id) {
		boolean phenomenonInDatabase = true;
		String query = "SELECT COUNT(phenomenon_id) FROM phenomenon WHERE phenomenon_id='"+phenomenon_id+"';";
		try {
			Statement stmt = con.createStatement();
			ResultSet rs = stmt.executeQuery(query);
			rs.next();
			if (rs.getInt("count") != 0) {
				phenomenonInDatabase = true;
			} else {
				phenomenonInDatabase = false;
			}
		} catch (SQLException e) {
			logger.warn("Invalid query: "+ query, e);
			e.printStackTrace();
		}
		return phenomenonInDatabase;
	}