public void insertMeasurement(Date date, String procedure_id, String feature_of_interest_id, String phenomenon_id, String offering_id, double value ){
		String query = "INSERT INTO observation (time_stamp, procedure_id, feature_of_interest_id,phenomenon_id,offering_id,numeric_value) values ('"+date+"', '"+procedure_id+"', '"+feature_of_interest_id+"','"+phenomenon_id+"','"+offering_id+"','"+value+"');"; 
		//logger.info(query);
		try {
			Statement stmt = con.createStatement();
			stmt.executeUpdate(query, Statement.RETURN_GENERATED_KEYS);
			//save the keys for linking to quality table
			ResultSet keyset = stmt.getGeneratedKeys();
			keyset.next();
			//save the observation id
			int observation_id = keyset.getInt("observation_id");
			//create new row in the quality table for the observation
			this.writeQuality(observation_id);
		} catch (SQLException e) {
			logger.warn("Invalid query: "+ query, e);
			e.printStackTrace();
		}
		
	}