more refactoring (not limited to attribute handling)

* completed separation of attributes and standard (column) values
* improved tests a lot

That work is still not finished, so expect things to fail horribly.

git-svn-id: http://svn.openslx.org/svn/openslx/trunk@1443 95ad53e4-c205-0410-b2fa-d234c58c8868

3 files changed, 661 insertions, 356 deletions

diff --git a/config-db/OpenSLX/ConfigDB.pm b/config-db/OpenSLX/ConfigDB.pm
index 95183c95..289f6f7f 100644
--- a/config-db/OpenSLX/ConfigDB.pm
+++ b/config-db/OpenSLX/ConfigDB.pm
@@ -561,6 +561,15 @@ sub fetchSystemByFilter
 		$filter, $resultCols, $attrFilter
 	);
 
+	# unless specific result cols have been given, we mix in the attributes
+	# of each system, too:
+	if (!defined $resultCols) {
+		foreach my $system (@systems) {
+			$system->{attrs} 
+				= $self->{'meta-db'}->fetchSystemAttrs($system->{id});
+		}
+	}
+
 	return wantarray() ? @systems : shift @systems;
 }
 
@@ -596,91 +605,16 @@ sub fetchSystemByID
 	
 	# unless specific result cols have been given, we mix in the attributes
 	# of each system, too:
-#	if (!defined $resultCols) {
-#		foreach my $system (@systems) {
-#			$system->{attrs} 
-#				= $self->{'meta-db'}->fetchSystemAttrs($system->{id});
-#		}
-#	}
+	if (!defined $resultCols) {
+		foreach my $system (@systems) {
+			$system->{attrs} 
+				= $self->{'meta-db'}->fetchSystemAttrs($system->{id});
+		}
+	}
 
 	return wantarray() ? @systems : shift @systems;
 }
 
-=item C<fetchSystemAttrs($systemID, [$attrNames])>
-
-Fetches and returns the information about the attributes of the system
-with the given ID.
-
-=over
-
-=item Param C<$systemID>
-
-The ID of the system whose attributes you are interested in.
-
-=item Param C<$attrNames> [Optional]
-
-A comma-separated list of attribute names that shall be returned. If not 
-defined,all available attributes will be returned.
-
-=item Return Value
-
-An array of hash-refs containing the resulting data rows (or a single hash-ref
-mapping all attribute names to the respective value).
-
-=back
-
-=cut
-
-sub fetchSystemAttrs
-{
-	my $self      = shift;
-	my $systemID  = shift;
-	my $attrNames = shift;
-
-	my @attrs = $self->{'meta-db'}->fetchSystemAttrs($systemID, $attrNames);
-
-	return wantarray() ? @attrs : shift @attrs;
-}
-
-=item C<fetchSystemAttrsAsHash($systemID, [$attrNames])>
-
-Fetches and returns the information about the attributes of the system
-with the given ID.
-
-=over
-
-=item Param C<$systemID>
-
-The ID of the system whose attributes you are interested in.
-
-=item Param C<$attrNames> [Optional]
-
-A comma-separated list of attribute names that shall be returned. If not 
-defined,all available attributes will be returned.
-
-=item Return Value
-
-A single hash-ref mapping all attribute names to their respective value.
-
-=back
-
-=cut
-
-sub fetchSystemAttrsAsHash
-{
-	my $self      = shift;
-	my $systemID  = shift;
-	my $attrNames = shift;
-
-	my @attrs = $self->{'meta-db'}->fetchSystemAttrs($systemID, $attrNames);
-
-	my $Result = {};
-	foreach my $attr (@attrs) {
-		$Result->{$attr->{name}} = $attr->{value};
-	}
-	return $Result;
-}
-
 =item C<fetchSystemIDsOfExport($id)>
 
 Fetches the IDs of all systems that make use of the export with the given ID.
@@ -787,10 +721,23 @@ An array of hash-refs containing the resulting data rows.
 
 sub fetchClientByFilter
 {
-	my $self   = shift;
-	my $filter = shift;
+	my $self       = shift;
+	my $filter     = shift;
+	my $resultCols = shift;
+	my $attrFilter = shift;
 
-	my @clients = $self->{'meta-db'}->fetchClientByFilter($filter);
+	my @clients = $self->{'meta-db'}->fetchClientByFilter(
+		$filter, $resultCols, $attrFilter
+	);
+
+	# unless specific result cols have been given, we mix in the attributes
+	# of each client, too:
+	if (!defined $resultCols) {
+		foreach my $client (@clients) {
+			$client->{attrs} 
+				= $self->{'meta-db'}->fetchClientAttrs($client->{id});
+		}
+	}
 
 	return wantarray() ? @clients : shift @clients;
 }
@@ -825,6 +772,15 @@ sub fetchClientByID
 
 	my @clients = $self->{'meta-db'}->fetchClientByID($ids, $resultCols);
 
+	# unless specific result cols have been given, we mix in the attributes
+	# of each client, too:
+	if (!defined $resultCols) {
+		foreach my $client (@clients) {
+			$client->{attrs} 
+				= $self->{'meta-db'}->fetchClientAttrs($client->{id});
+		}
+	}
+
 	return wantarray() ? @clients : shift @clients;
 }
 
@@ -911,8 +867,20 @@ sub fetchGroupByFilter
 	my $self       = shift;
 	my $filter     = shift;
 	my $resultCols = shift;
+	my $attrFilter = shift;
 
-	my @groups = $self->{'meta-db'}->fetchGroupByFilter($filter, $resultCols);
+	my @groups = $self->{'meta-db'}->fetchGroupByFilter(
+		$filter, $resultCols, $attrFilter
+	);
+
+	# unless specific result cols have been given, we mix in the attributes
+	# of each group, too:
+	if (!defined $resultCols) {
+		foreach my $group (@groups) {
+			$group->{attrs} 
+				= $self->{'meta-db'}->fetchGroupAttrs($group->{id});
+		}
+	}
 
 	return wantarray() ? @groups : shift @groups;
 }
@@ -947,6 +915,15 @@ sub fetchGroupByID
 
 	my @groups = $self->{'meta-db'}->fetchGroupByID($ids, $resultCols);
 
+	# unless specific result cols have been given, we mix in the attributes
+	# of each group, too:
+	if (!defined $resultCols) {
+		foreach my $group (@groups) {
+			$group->{attrs} 
+				= $self->{'meta-db'}->fetchGroupAttrs($group->{id});
+		}
+	}
+
 	return wantarray() ? @groups : shift @groups;
 }
 
@@ -1707,6 +1684,43 @@ sub changeClient
 	return $self->{'meta-db'}->changeClient($clientIDs, $valRows);
 }
 
+=item C<setClientAttr($clientID, $attrName, $attrValue)>
+
+Sets a value for an attribute of the given client. If the client already
+has a value for this attribute, it will be overwritten.
+
+=over
+
+=item Param C<clientID>
+
+The ID of the client whose attribute shall be changed.
+
+=item Param C<attrName>
+
+The name of the attribute to change.
+
+=item Param C<attrValue>
+
+The new value for the attribute.
+
+=item Return Value
+
+C<1> if the attribute could be set, C<undef> if not.
+
+=back
+
+=cut
+
+sub setClientAttr
+{
+	my $self      = shift;
+	my $clientID  = shift;
+	my $attrName  = shift;
+	my $attrValue = shift;
+
+	return $self->{'meta-db'}->setClientAttr($clientID, $attrName, $attrValue);
+}
+
 =item C<setSystemIDsOfClient($clientID, @$systemIDs)>
 
 Specifies all systems that should be offered for booting by the given client.
@@ -1987,6 +2001,43 @@ sub removeGroup
 	return $self->{'meta-db'}->removeGroup($groupIDs);
 }
 
+=item C<setGroupAttr($groupID, $attrName, $attrValue)>
+
+Sets a value for an attribute of the given group. If the group already
+has a value for this attribute, it will be overwritten.
+
+=over
+
+=item Param C<groupID>
+
+The ID of the group whose attribute shall be changed.
+
+=item Param C<attrName>
+
+The name of the attribute to change.
+
+=item Param C<attrValue>
+
+The new value for the attribute.
+
+=item Return Value
+
+C<1> if the attribute could be set, C<undef> if not.
+
+=back
+
+=cut
+
+sub setGroupAttr
+{
+	my $self      = shift;
+	my $groupID  = shift;
+	my $attrName  = shift;
+	my $attrValue = shift;
+
+	return $self->{'meta-db'}->setGroupAttr($groupID, $attrName, $attrValue);
+}
+
 =item C<changeGroup(@$groupIDs, @$valRows)>
 
 Changes the data of one or more groups.
@@ -2588,13 +2639,17 @@ sub mergeAttributes
 	my $target = shift;
 	my $source = shift;
 
-	foreach my $key (keys %$source) {
-		next if !isAttribute($key);
-		my $sourceVal = $source->{$key} || '';
-		my $targetVal = $target->{$key} || '';
-		if (length($sourceVal) && !length($targetVal)) {
-			vlog(3, _tr("merging %s (val=%s)", $key, $sourceVal));
-			$target->{$key} = $sourceVal;
+	my $sourceAttrs = $source->{attrs} || {};
+
+	$target->{attrs} ||= {};
+	my $targetAttrs = $target->{attrs};
+
+	foreach my $key (keys %$sourceAttrs) {
+		my $sourceVal = $sourceAttrs->{$key};
+		my $targetVal = $targetAttrs->{$key};
+		if (defined $sourceVal && !defined $targetVal) {
+			vlog(0, _tr("merging %s (val=%s)", $key, $sourceVal));
+			$targetAttrs->{$key} = $sourceVal;
 		}
 	}
 
@@ -2628,11 +2683,16 @@ sub pushAttributes
 	my $target = shift;
 	my $source = shift;
 
-	foreach my $key (grep { isAttribute($_) } keys %$source) {
-		my $sourceVal = $source->{$key} || '';
-		if (length($sourceVal)) {
+	my $sourceAttrs = $source->{attrs} || {};
+
+	$target->{attrs} ||= {};
+	my $targetAttrs = $target->{attrs};
+
+	foreach my $key (keys %$sourceAttrs) {
+		my $sourceVal = $sourceAttrs->{$key};
+		if (defined $sourceVal) {
 			vlog(3, _tr("pushing %s (val=%s)", $key, $sourceVal));
-			$target->{$key} = $sourceVal;
+			$targetAttrs->{$key} = $sourceVal;
 		}
 	}
 
@@ -2826,54 +2886,7 @@ sub _checkAndUpgradeDBSchemaIfNecessary
 				$DbSchema->{version}, $currVersion
 			)
 		);
-		foreach my $v (sort { $a <=> $b } keys %DbSchemaHistory) {
-			next if $v <= $currVersion;
-			my $changeSet = $DbSchemaHistory{$v};
-			foreach my $c (0 .. scalar(@$changeSet) - 1) {
-				my $changeDescr = @{$changeSet}[$c];
-				my $cmd         = $changeDescr->{cmd};
-				if ($cmd eq 'add-table') {
-					$metaDB->schemaAddTable(
-						$changeDescr->{'table'},
-						$changeDescr->{'cols'},
-						$changeDescr->{'vals'}
-					);
-				} elsif ($cmd eq 'drop-table') {
-					$metaDB->schemaDropTable($changeDescr->{'table'});
-				} elsif ($cmd eq 'rename-table') {
-					$metaDB->schemaRenameTable(
-						$changeDescr->{'old-table'},
-						$changeDescr->{'new-table'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'add-columns') {
-					$metaDB->schemaAddColumns(
-						$changeDescr->{'table'},
-						$changeDescr->{'new-cols'},
-						$changeDescr->{'new-default-vals'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'drop-columns') {
-					$metaDB->schemaDropColumns(
-						$changeDescr->{'table'},
-						$changeDescr->{'drop-cols'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'rename-columns') {
-					$metaDB->schemaRenameColumns(
-						$changeDescr->{'table'},
-						$changeDescr->{'col-renames'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'perl-func') {
-					if (!$changeDescr->{code}->($self)) {
-						croak _tr('problem in perl-func cmd!');
-					}
-				} else {
-					croak _tr('UnknownDbSchemaCommand', $cmd);
-				}
-			}
-		}
+		$metaDB->schemaUpgradeDBFrom($currVersion);
 		$metaDB->schemaSetDBVersion($DbSchema->{version});
 		vlog(1, _tr('upgrade done'));
 	} else {
diff --git a/config-db/OpenSLX/DBSchema.pm b/config-db/OpenSLX/DBSchema.pm
index 54596c9f..801f50a9 100644
--- a/config-db/OpenSLX/DBSchema.pm
+++ b/config-db/OpenSLX/DBSchema.pm
@@ -33,12 +33,7 @@ use OpenSLX::Basics;
 
 use POSIX qw(locale_h);
 my $lang = setlocale(LC_MESSAGES);
-my $country;
-if ($lang =~ m[^\w\w_(\w\w)]) {
-	$country = lc($1);
-} else {
-	$country = 'us';
-}
+my $country = $lang =~ m[^\w\w_(\w\w)] ? lc($1) : 'us';
 
 ################################################################################
 ### DB-schema definition
@@ -73,12 +68,22 @@ $DbSchema = {
 			],
 			'vals' => [
 				{	# add default client
-					'id' => 0,
-					'name' => '<<<default>>>',
-					'comment' => 'internal client that holds default values',
+					'id'         => 0,
+					'name'       => '<<<default>>>',
+					'comment'    => 'internal client that holds default values',
+					'unbootable' => 0,
 				},
 			],
 		},
+		'client_attr' => {
+			# attributes of clients
+			'cols' => [
+				'id:pk',			# primary key
+				'client_id:fk',		# foreign key to client
+				'name:s.128',		# attribute name
+				'value:s.255',		# attribute value
+			],
+		},
 		'client_system_ref' => {
 			# clients referring to the systems they should offer for booting
 			'cols' => [
@@ -134,6 +139,15 @@ $DbSchema = {
 				'comment:s.1024',	# internal comment (optional, for admins)
 			],
 		},
+		'group_attr' => {
+			# attributes of groups
+			'cols' => [
+				'id:pk',			# primary key
+				'group_id:fk',		# foreign key to group
+				'name:s.128',		# attribute name
+				'value:s.255',		# attribute value
+			],
+		},
 		'group_client_ref' => {
 			# groups referring to their clients
 			'cols' => [
@@ -394,146 +408,9 @@ $DbSchema = {
 };
 
 ################################################################################
-### DB-schema history
-###
-### 	This hash contains a description of all the different changes that have
-### 	taken place on the schema. Each version contains a changeset (array)
-### 	with the commands that take the schema from the last version to the
-### 	current.
-###
-### 	The following 'cmd'-types are supported:
-###
-### 		add-table => creates a new table
-### 			'table' => contains the name of the new table
-### 			'cols'	=> contains a list of column descriptions
-### 			'vals'	=> optional, contains list of data hashes to be inserted
-### 					   into new table
-###
-### 		drop-table => drops an existing table
-### 			'table	=> contains the name of the table to be dropped
-###
-### 		rename-table => renames a table
-### 			'old-table' => contains the old name of the table
-### 			'new-table' => contains the new name of the table
-### 			'cols' => contains a full list of column descriptions
-###
-### 		add-columns => adds columns to a table
-### 			'table' => the name of the table the columns should be added to
-### 			'new-cols' => contains a list of new column descriptions
-### 			'new-default-vals' => optional, a list of data hashes to be used
-###							 		  as default values for the new columns
-### 			'cols' => contains a full list of resulting column descriptions
-###
-### 		drop-columns => drops columns from a table
-### 			'table' => the name of the table the columns should be dropped from
-### 			'drop-cols' => a list of column names to be dropped
-### 			'cols'	=> contains a full list of resulting column descriptions
-###
-###			perl-func => a perl function invoked with config-DB object as param
-### 			'code'	=> the function (sub) that shall be executed
-###
-################################################################################
-
-%DbSchemaHistory = (
-	'0.01' => [
-		# there's no need to upgrade to the initial schema version, as we
-		# create the newest schema automatically if none exists yet.
-	],
-	'0.2' => [
-		# move attributes into separate tables ...
-		#
-		# ... system attributes ...
-		{
-			'cmd' => 'add-table',
-			'table' => 'system_attr',
-			'cols' => [
-				'id:pk',
-				'system_id:fk',
-				'name:s.128',
-				'value:s.255',
-			],
-		},
-		{
-			'cmd' => 'perl-func',
-			'code' => sub {
-				my $configDB = shift;
-				foreach my $system ($configDB->fetchSystemByFilter()) {
-					foreach my $key (keys %$system) {
-						next if substr($key, 0, 5) ne 'attr_';
-						my $attrValue = $system->{$key} || '';
-						next if $system->{id}>0 && !length($attrValue);
-						my $newAttrName = substr($key, 5);
-						$configDB->setSystemAttr(
-							$system->{id}, $newAttrName, $attrValue
-						);
-					}
-				}
-				1;
-			}
-		},
-		{
-			'cmd' => 'drop-columns',
-			'table' => 'system',
-			'drop-cols' => [
-				'attr_automnt_dir',
-				'attr_automnt_src',
-				'attr_country',
-				'attr_dm_allow_shutdown',
-				'attr_hw_graphic',
-				'attr_hw_monitor',
-				'attr_hw_mouse',
-				'attr_late_dm',
-				'attr_netbios_workgroup',
-				'attr_nis_domain',
-				'attr_nis_servers',
-				'attr_ramfs_fsmods',
-				'attr_ramfs_miscmods',
-				'attr_ramfs_nicmods',
-				'attr_ramfs_screen',
-				'attr_sane_scanner',
-				'attr_scratch',
-				'attr_slxgrp',
-				'attr_start_alsasound',
-				'attr_start_atd',
-				'attr_start_cron',
-				'attr_start_dreshal',
-				'attr_start_ntp',
-				'attr_start_nfsv4',
-				'attr_start_printer',
-				'attr_start_samba',
-				'attr_start_snmp',
-				'attr_start_sshd',
-				'attr_start_syslog',
-				'attr_start_x',
-				'attr_start_xdmcp',
-				'attr_tex_enable',
-				'attr_timezone',
-				'attr_tvout',
-				'attr_vmware',
-			],
-			'cols' => [
-				'id:pk',
-				'export_id:fk',
-				'name:s.64',
-				'label:s.64',
-				'kernel:s.128',
-				'kernel_params:s.512',
-				'hidden:b',
-				'comment:s.1024',
-			],
-		},
-		#
-		# ... client attributes ...
-		#
-		# ... group attributes ...
-	],
-);
-
-
-################################################################################
 ###
-### Load all available AttrInfo modules and build the complete hash containing
-### info about all known attributes from that.
+### Load the available AttrInfo-modules and build a hash containing info about
+### all known attributes from the data contained in those modules.
 ###
 ################################################################################
 
diff --git a/config-db/OpenSLX/MetaDB/DBI.pm b/config-db/OpenSLX/MetaDB/DBI.pm
index 774ab90e..98754777 100644
--- a/config-db/OpenSLX/MetaDB/DBI.pm
+++ b/config-db/OpenSLX/MetaDB/DBI.pm
@@ -78,14 +78,13 @@ sub _trim
 
 sub _buildFilterClause
 {
-	my $self      = shift;
-	my $filter    = shift || {};
-	my $connector = shift;
+	my $self         = shift;
+	my $filter       = shift || {};
+	my $filterClause = shift || '';
 
-	my $filterClause = '';
-	my ($quotedVal);
+	my ($connector, $quotedVal);
 	foreach my $col (keys %$filter) {
-		$connector = !defined $connector ? 'WHERE' : 'AND';
+		$connector = !length($filterClause) ? 'WHERE' : 'AND';
 		if (defined $filter->{$col}) {
 			$quotedVal = $self->{dbh}->quote($filter->{$col});
 			$filterClause .= " $connector $col = $quotedVal";
@@ -94,42 +93,48 @@ sub _buildFilterClause
 		}
 	}
 	
-	return $filterClause;
+	return $filterClause || '';
 }
 
 sub _buildAttrFilterClause
 {
-	my $self       = shift;
-	my $attrFilter = shift || {};
-	my $connector = shift;
+	my $self         = shift;
+	my $attrFilter   = shift || {};
+	my $table        = shift;
+	my $filterClause = shift || '';
+
+	my %tableMap = (
+		'client' => 'client',
+		'group'  => 'groups',
+		'system' => 'system',
+	);
 
-	my $attrFilterClause = '';
-	my ($quotedName, $quotedValue);
+	my ($connector, $quotedName, $quotedValue);
 	foreach my $name (keys %$attrFilter) {
-		$connector = !defined $connector ? 'WHERE' : 'AND';
+		$connector = !length($filterClause) ? 'WHERE' : 'AND';
 		$quotedName = $self->{dbh}->quote($name);
 		if (defined $attrFilter->{$name}) {
 			$quotedValue = $self->{dbh}->quote($attrFilter->{$name});
-			$attrFilterClause .= <<"			End-of-Here";
+			$filterClause .= <<"			End-of-Here";
 				$connector EXISTS (
-					SELECT name FROM system_attr
+					SELECT name FROM ${table}_attr
 					WHERE name = $quotedName 
 					AND value = $quotedValue
-					AND system_id = system.id
+					AND ${table}_id = $tableMap{$table}.id
 				)
 			End-of-Here
 		} else {
-			$attrFilterClause .= <<"			End-of-Here";
+			$filterClause .= <<"			End-of-Here";
 				$connector NOT EXISTS (
-					SELECT name FROM system_attr
+					SELECT name FROM ${table}_attr
 					WHERE name = $quotedName 
-					AND system_id = system.id
+					AND ${table}_id = $tableMap{$table}.id
 				)
 			End-of-Here
 		}
 	}
 
-	return $attrFilterClause;
+	return $filterClause;
 }
 
 sub _doSelect
@@ -245,13 +250,13 @@ sub fetchSystemByFilter
 	my $attrFilter = shift;
 
 	$resultCols = '*' unless (defined $resultCols);
-	my $filterClause = $self->_buildFilterClause($filter, 'AND');
-	my $attrFilterClause = $self->_buildAttrFilterClause($attrFilter, 'AND');
+	my $filterClause = $self->_buildFilterClause($filter);
+	$filterClause = $self->_buildAttrFilterClause(
+		$attrFilter, 'system', $filterClause
+	);
 	my $sql = <<"	End-of-Here";
 		SELECT $resultCols FROM system
-		WHERE 1=1
 		$filterClause
-		$attrFilterClause
 	End-of-Here
 	return $self->_doSelect($sql);
 }
@@ -273,17 +278,17 @@ sub fetchSystemAttrs
 {
 	my $self      = shift;
 	my $systemID  = $self->{dbh}->quote(shift);
-	my $attrNames = shift;
 
 	my $sql = <<"	End-of-Here";
-		SELECT id, name, value FROM system_attr
+		SELECT name, value FROM system_attr
 		WHERE system_id = $systemID
 	End-of-Here
-	if (defined $attrNames) {
-		my $attrList = join ',', map { $self->{dbh}->quote($_) } @$attrNames;
-		$sql .= " AND name IN ($attrList)";
+	my @attrs = $self->_doSelect($sql);
+	my $Result = {};
+	foreach my $attr (@attrs) {
+		$Result->{$attr->{name}} = $attr->{value};
 	}
-	return $self->_doSelect($sql);
+	return $Result;
 }
 
 sub fetchSystemIDsOfExport
@@ -324,10 +329,17 @@ sub fetchClientByFilter
 	my $self       = shift;
 	my $filter     = shift;
 	my $resultCols = shift;
+	my $attrFilter = shift;
 
 	$resultCols = '*' unless (defined $resultCols);
 	my $filterClause = $self->_buildFilterClause($filter);
-	my $sql = "SELECT $resultCols FROM client $filterClause";
+	$filterClause = $self->_buildAttrFilterClause(
+		$attrFilter, 'client', $filterClause
+	);
+	my $sql = <<"	End-of-Here";
+		SELECT $resultCols FROM client
+		$filterClause
+	End-of-Here
 	return $self->_doSelect($sql);
 }
 
@@ -344,6 +356,23 @@ sub fetchClientByID
 	return $self->_doSelect($sql);
 }
 
+sub fetchClientAttrs
+{
+	my $self     = shift;
+	my $clientID = $self->{dbh}->quote(shift);
+
+	my $sql = <<"	End-of-Here";
+		SELECT name, value FROM client_attr
+		WHERE client_id = $clientID
+	End-of-Here
+	my @attrs = $self->_doSelect($sql);
+	my $Result = {};
+	foreach my $attr (@attrs) {
+		$Result->{$attr->{name}} = $attr->{value};
+	}
+	return $Result;
+}
+
 sub fetchClientIDsOfSystem
 {
 	my $self     = shift;
@@ -371,10 +400,17 @@ sub fetchGroupByFilter
 	my $self       = shift;
 	my $filter     = shift;
 	my $resultCols = shift;
+	my $attrFilter = shift;
 
 	$resultCols = '*' unless (defined $resultCols);
 	my $filterClause = $self->_buildFilterClause($filter);
-	my $sql = "SELECT $resultCols FROM groups $filterClause";
+	$filterClause = $self->_buildAttrFilterClause(
+		$attrFilter, 'group', $filterClause
+	);
+	my $sql = <<"	End-of-Here";
+		SELECT $resultCols FROM groups
+		$filterClause
+	End-of-Here
 	return $self->_doSelect($sql);
 }
 
@@ -391,6 +427,23 @@ sub fetchGroupByID
 	return $self->_doSelect($sql);
 }
 
+sub fetchGroupAttrs
+{
+	my $self    = shift;
+	my $groupID = $self->{dbh}->quote(shift);
+
+	my $sql = <<"	End-of-Here";
+		SELECT name, value FROM group_attr
+		WHERE group_id = $groupID
+	End-of-Here
+	my @attrs = $self->_doSelect($sql);
+	my $Result = {};
+	foreach my $attr (@attrs) {
+		$Result->{$attr->{name}} = $attr->{value};
+	}
+	return $Result;
+}
+
 sub fetchGroupIDsOfSystem
 {
 	my $self     = shift;
@@ -505,20 +558,22 @@ sub _doUpdate
 
 	my $dbh    = $self->{'dbh'};
 	my $valRow = (@$valRows)[0];
-	return if !defined $valRow || !scalar keys %$valRow;
+	return 1 if !defined $valRow || !scalar keys %$valRow;
 
 	my $idx = 0;
 	foreach my $valRow (@$valRows) {
 		my $id      = $IDs->[$idx++];
 		my %valData = %$valRow;
-		delete $valData{'id'};
-		# filter column 'id' if present, as we don't want to update it
+		# fail if asked to change the column 'id', as that is bogus
+		return if exists $valData{id} && $valData{id} ne $id;
+		# filter column 'id' if present, as we don't want to write it
+		delete $valData{id};
 		my @cols = map { "$_ = " . $self->quote($valRow->{$_}) }
 		  grep { $_ ne 'id' }
 		  # filter column 'id' if present, as we don't want
 		  # to update it!
 		  keys %$valRow;
-		return if !@cols;
+		next if !@cols;
 		my $cols = join ', ', @cols;
 		my $sql = "UPDATE $table SET $cols";
 		if (defined $id) {
@@ -661,7 +716,26 @@ sub addSystem
 	my $self    = shift;
 	my $valRows = shift;
 
-	return $self->_doInsert('system', $valRows);
+	# separate the attribute hashes ...
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+
+	# ... store the systems to get the IDs ...
+	my @systemIDs = $self->_doInsert('system', $valRows);
+
+	# ... finally store the individual attribute sets
+	foreach my $id (@systemIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setSystemAttrs($id, $attrs);
+	}
+
+	return @systemIDs;
 }
 
 sub removeSystem
@@ -678,37 +752,44 @@ sub changeSystem
 	my $systemIDs = shift;
 	my $valRows   = shift;
 
+	# separate the attribute hashes and store them individually
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+	foreach my $id (@$systemIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setSystemAttrs($id, $attrs);
+	}
+
+	# finally update all systems in one go
 	return $self->_doUpdate('system', $systemIDs, $valRows);
 }
 
-sub setSystemAttr
+sub setSystemAttrs
 {
-	my $self      = shift;
-	my $systemID  = shift;
-	my $attrName  = shift;
-	my $attrValue = shift;
-
-	my $quotedSystemID  = $self->{dbh}->quote($systemID);
-	my $quotedAttrName  = $self->{dbh}->quote($attrName);
-
-	my $sql = <<"	End-of-Here";
-		SELECT id FROM system_attr
-		WHERE system_id = $quotedSystemID
-		AND name = $quotedAttrName
-	End-of-Here
-	my $id = $self->_doSelect($sql, 'id');
-	if ($id) {
-		return $self->_doUpdate(
-			'system_attr', [ $id ], [ { value => $attrValue } ] 
+	my $self     = shift;
+	my $systemID = shift;
+	my $attrs    = shift;
+
+	# we take the simple path and remove all attributes ...
+	return if !$self->_doDelete('system_attr', [ $systemID ], 'system_id');
+
+	# ... and (re-)insert the given ones
+	foreach my $key (keys %$attrs) {
+		return if !$self->_doInsert(
+			'system_attr', [ {
+				system_id => $systemID,
+				name      => $key,
+				value     => $attrs->{$key},
+			} ]
 		);
 	}
-	return $self->_doInsert(
-		'system_attr', [ { 
-			system_id => $systemID,
-			name      => $attrName,
-			value     => $attrValue,
-		} ] 
-	);
+	return 1;
 }
 
 sub setClientIDsOfSystem
@@ -742,7 +823,26 @@ sub addClient
 	my $self    = shift;
 	my $valRows = shift;
 
-	return $self->_doInsert('client', $valRows);
+	# separate the attribute hashes ...
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+
+	# ... store the clients to get the IDs ...
+	my @clientIDs = $self->_doInsert('client', $valRows);
+
+	# ... finally store the individual attribute sets
+	foreach my $id (@clientIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setClientAttrs($id, $attrs);
+	}
+
+	return @clientIDs;
 }
 
 sub removeClient
@@ -759,9 +859,46 @@ sub changeClient
 	my $clientIDs = shift;
 	my $valRows   = shift;
 
+	# separate the attribute hashes and store them individually
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+	foreach my $id (@$clientIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setClientAttrs($id, $attrs);
+	}
+
+	# finally update all systems in one go
 	return $self->_doUpdate('client', $clientIDs, $valRows);
 }
 
+sub setClientAttrs
+{
+	my $self     = shift;
+	my $clientID = shift;
+	my $attrs    = shift;
+
+	# we take the simple path and remove all attributes ...
+	return if !$self->_doDelete('client_attr', [ $clientID ], 'client_id');
+
+	# ... and (re-)insert the given ones
+	foreach my $key (keys %$attrs) {
+		return if !$self->_doInsert(
+			'client_attr', [ {
+				client_id => $clientID,
+				name      => $key,
+				value     => $attrs->{$key},
+			} ]
+		);
+	}
+	return 1;
+}
+
 sub setSystemIDsOfClient
 {
 	my $self      = shift;
@@ -793,7 +930,26 @@ sub addGroup
 	my $self    = shift;
 	my $valRows = shift;
 
-	return $self->_doInsert('groups', $valRows);
+	# separate the attribute hashes ...
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+
+	# ... store the groups to get the IDs ...
+	my @groupIDs = $self->_doInsert('groups', $valRows);
+
+	# ... finally store the individual attribute sets
+	foreach my $id (@groupIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setGroupAttrs($id, $attrs);
+	}
+
+	return @groupIDs;
 }
 
 sub removeGroup
@@ -810,9 +966,46 @@ sub changeGroup
 	my $groupIDs = shift;
 	my $valRows  = shift;
 
+	# separate the attribute hashes and store them individually
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+	foreach my $id (@$groupIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setGroupAttrs($id, $attrs);
+	}
+
+	# finally update all groups in one go
 	return $self->_doUpdate('groups', $groupIDs, $valRows);
 }
 
+sub setGroupAttrs
+{
+	my $self    = shift;
+	my $groupID = shift;
+	my $attrs   = shift;
+
+	# we take the simple path and remove all attributes ...
+	return if !$self->_doDelete('group_attr', [ $groupID ], 'group_id');
+
+	# ... and (re-)insert the given ones
+	foreach my $key (keys %$attrs) {
+		return if !$self->_doInsert(
+			'group_attr', [ {
+				group_id => $groupID,
+				name      => $key,
+				value     => $attrs->{$key},
+			} ]
+		);
+	}
+	return 1;
+}
+
 sub setClientIDsOfGroup
 {
 	my $self      = shift;
@@ -896,6 +1089,16 @@ sub schemaFetchDBVersion
 	return $row->{schema_version};
 }
 
+sub schemaUpgradeDBFrom
+{
+	my $self        = shift;
+	my $currVersion = shift;
+
+	$self->_upgradeDBTo0_2() if $currVersion < 0.2;
+
+	return 1;
+}
+
 sub schemaSetDBVersion
 {
 	my $self      = shift;
@@ -1114,6 +1317,218 @@ sub schemaChangeColumns
 	return;
 }
 
+sub _upgradeDBTo0_2
+{
+	my $self = shift;
+
+	# move attributes into separate tables ...
+	#
+	# ... system attributes ...
+	$self->schemaAddTable(
+		'system_attr', 
+		[
+			'id:pk',
+			'system_id:fk',
+			'name:s.128',
+			'value:s.255',
+		]
+	);
+	foreach my $system ($self->fetchSystemByFilter()) {
+		my %attrs;
+		foreach my $key (keys %$system) {
+			next if substr($key, 0, 5) ne 'attr_';
+			my $attrValue = $system->{$key} || '';
+			next if $system->{id} > 0 && !length($attrValue);
+			my $newAttrName = substr($key, 5);
+			$attrs{$newAttrName} = $attrValue;
+		}
+		$self->setSystemAttrs($system->{id}, \%attrs);
+	}
+	$self->schemaDropColumns(
+		'system',
+		[
+			'attr_automnt_dir',
+			'attr_automnt_src',
+			'attr_country',
+			'attr_dm_allow_shutdown',
+			'attr_hw_graphic',
+			'attr_hw_monitor',
+			'attr_hw_mouse',
+			'attr_late_dm',
+			'attr_netbios_workgroup',
+			'attr_nis_domain',
+			'attr_nis_servers',
+			'attr_ramfs_fsmods',
+			'attr_ramfs_miscmods',
+			'attr_ramfs_nicmods',
+			'attr_ramfs_screen',
+			'attr_sane_scanner',
+			'attr_scratch',
+			'attr_slxgrp',
+			'attr_start_alsasound',
+			'attr_start_atd',
+			'attr_start_cron',
+			'attr_start_dreshal',
+			'attr_start_ntp',
+			'attr_start_nfsv4',
+			'attr_start_printer',
+			'attr_start_samba',
+			'attr_start_snmp',
+			'attr_start_sshd',
+			'attr_start_syslog',
+			'attr_start_x',
+			'attr_start_xdmcp',
+			'attr_tex_enable',
+			'attr_timezone',
+			'attr_tvout',
+			'attr_vmware',
+		],
+		[
+			'id:pk',
+			'export_id:fk',
+			'name:s.64',
+			'label:s.64',
+			'kernel:s.128',
+			'kernel_params:s.512',
+			'hidden:b',
+			'comment:s.1024',
+		]
+	);
+	#
+	# ... client attributes ...
+	$self->schemaAddTable(
+		'client_attr',
+		[
+			'id:pk',
+			'client_id:fk',
+			'name:s.128',
+			'value:s.255',
+		]
+	);
+	foreach my $client ($self->fetchClientByFilter()) {
+		my %attrs;
+		foreach my $key (keys %$client) {
+			next if substr($key, 0, 5) ne 'attr_';
+			my $attrValue = $client->{$key} || '';
+			next if !length($attrValue);
+			my $newAttrName = substr($key, 5);
+			$attrs{$newAttrName} = $attrValue;
+		}
+		$self->setClientAttrs($client->{id}, \%attrs);
+	}
+	$self->schemaDropColumns(
+		'client',
+		[
+			'attr_automnt_dir',
+			'attr_automnt_src',
+			'attr_country',
+			'attr_dm_allow_shutdown',
+			'attr_hw_graphic',
+			'attr_hw_monitor',
+			'attr_hw_mouse',
+			'attr_late_dm',
+			'attr_netbios_workgroup',
+			'attr_nis_domain',
+			'attr_nis_servers',
+			'attr_sane_scanner',
+			'attr_scratch',
+			'attr_slxgrp',
+			'attr_start_alsasound',
+			'attr_start_atd',
+			'attr_start_cron',
+			'attr_start_dreshal',
+			'attr_start_ntp',
+			'attr_start_nfsv4',
+			'attr_start_printer',
+			'attr_start_samba',
+			'attr_start_snmp',
+			'attr_start_sshd',
+			'attr_start_syslog',
+			'attr_start_x',
+			'attr_start_xdmcp',
+			'attr_tex_enable',
+			'attr_timezone',
+			'attr_tvout',
+			'attr_vmware',
+		],
+		[
+			'id:pk',
+			'name:s.128',
+			'mac:s.20',
+			'boot_type:s.20',
+			'unbootable:b',
+			'kernel_params:s.128',
+			'comment:s.1024',
+		]
+	);
+	#
+	# ... group attributes ...
+	$self->schemaAddTable(
+		'group_attr',
+		[
+			'id:pk',
+			'group_id:fk',
+			'name:s.128',
+			'value:s.255',
+		]
+	);
+	foreach my $group ($self->fetchGroupByFilter()) {
+		my %attrs;
+		foreach my $key (keys %$group) {
+			next if substr($key, 0, 5) ne 'attr_';
+			my $attrValue = $group->{$key} || '';
+			next if !length($attrValue);
+			my $newAttrName = substr($key, 5);
+			$attrs{$newAttrName} = $attrValue;
+		}
+		$self->setGroupAttrs($group->{id}, \%attrs);
+	}
+	$self->schemaDropColumns(
+		'groups',
+		[
+			'attr_automnt_dir',
+			'attr_automnt_src',
+			'attr_country',
+			'attr_dm_allow_shutdown',
+			'attr_hw_graphic',
+			'attr_hw_monitor',
+			'attr_hw_mouse',
+			'attr_late_dm',
+			'attr_netbios_workgroup',
+			'attr_nis_domain',
+			'attr_nis_servers',
+			'attr_sane_scanner',
+			'attr_scratch',
+			'attr_slxgrp',
+			'attr_start_alsasound',
+			'attr_start_atd',
+			'attr_start_cron',
+			'attr_start_dreshal',
+			'attr_start_ntp',
+			'attr_start_nfsv4',
+			'attr_start_printer',
+			'attr_start_samba',
+			'attr_start_snmp',
+			'attr_start_sshd',
+			'attr_start_syslog',
+			'attr_start_x',
+			'attr_start_xdmcp',
+			'attr_tex_enable',
+			'attr_timezone',
+			'attr_tvout',
+			'attr_vmware',
+		],
+		[
+			'id:pk',
+			'name:s.128',
+			'priority:i',
+			'comment:s.1024',
+		]
+	);
+
+	return 1;
+}
+
 1;
 
 =head1 NAME