public void addProcedure(String procedure_id){
		// only add phenomenon to database if not yet added
				if (!this.isProcedureInDatabase(procedure_id)) {
					String query = "INSERT INTO procedure(procedure_id) VALUES ('" + procedure_id+"');";
					try {
						Statement stmt = con.createStatement();
						stmt.execute(query);
					} catch (SQLException e) {
						logger.warn("Invalid query: "+ query, e);
						e.printStackTrace();
					}
				}
	}