add database table/column comments

			}

		);

	},

	# v5 -> v6

	# Add documentation

	sub {

		my ($db) = @_;

		$db->query(

			qq{

				comment on table in_transit is 'Users who are currently checked into a train';

				comment on view in_transit_str is 'in_transit with station IDs resolved to name/ds100';

				comment on table journey_stats is 'Cache for yearly and monthly statistics in JSON format';

				comment on table journeys is 'Past train trips (i.e. the user has already checked out)';

				comment on view journeys_str is 'journeys with station IDs resolved to name/ds100';

				comment on table pending_mails is 'Blacklist for mail addresses used in an unsuccessful registration attempt. Helps ensure that travelynx does not spam individual mails with registration attempts.';

				comment on table stations is 'Map of station IDs to name and DS100 code';

				comment on table tokens is 'User API tokens';

				comment on column in_transit.route is 'Format: station1|station2|station3|...';

				comment on column in_transit.messages is 'Format: epoch:message1|epoch:message2|...';

				comment on column in_transit_str.route is 'Format: station1|station2|station3|...';

				comment on column in_transit_str.messages is 'Format: epoch:message1|epoch:message2|...';

				comment on column journeys.edited is 'Bit mask indicating which part has been entered manually. 0x0001 = sched departure, 0x0002 = real departure, 0x0100 = sched arrival, 0x0200 = real arrival';

				comment on column journeys.route is 'Format: station1|station2|station3|...';

				comment on column journeys.messages is 'Format: epoch:message1|epoch:message2|...';

				comment on column journeys_str.edited is 'Bit mask indicating which part has been entered manually. 0x0001 = sched departure, 0x0002 = real departure, 0x0100 = sched arrival, 0x0200 = real arrival';

				comment on column journeys_str.route is 'Format: station1|station2|station3|...';

				comment on column journeys_str.messages is 'Format: epoch:message1|epoch:message2|...';

				comment on column users.status is 'Bit mask: 0x01 = verified';

				comment on column users.public_level is 'Bit mask indicating public account parts. 0x01 = current status (checkin from/to or last checkout at)';

				comment on column users.token is 'Used for e-mail verification';

				comment on column users.deletion_requested is 'Time at which account deletion was requested';

				update schema_version set version = 6;

			}

		);

	},

);

sub setup_db {